Remove a peer's live routes when its session goes down (closes #56)

RIS sends no withdrawals for the routes of a peer whose BGP session goes
down, so those routes stayed in the live tables for good.

The streamer now hands STATE messages to the handlers that want them and
never drops one for backpressure: it waits for room in a full queue until
the idle timer drops the connection. When the prefix handler gets one whose
state is down, it drops the peer's updates still in its batch and notes the
peer; the next flush deletes all of the peer's live routes, IPv4 and IPv6,
before writing the batch, so updates the peer sends after the down are
kept. The live route tables' unique key now leads with peer_ip, so it also
finds a peer's routes.

Model: opus-5-5

.dockerignore

@@ -0,0 +1,32 @@
+# Docker does not read .gitignore, and a pattern here matches from the root of
+# the build context only: a pattern meant for every directory needs `**/`.
+
+# .git is sent without its config. Without a VERSION build argument the
+# stage that compiles runs `git describe --tags --always` on .git, which
+# does not need .git/config; that file can hold a credential, such as a
+# password in a remote URL or the token the CI checkout step stores there.
+.git/config
+
+# Local build and debug output: `make build`, `make run`, `make asupdate`, test
+# binaries, coverage profiles and source archives.
+/bin
+/log.txt
+/out
+/pkg/asinfo/asdata.json
+**/*.tar.zst
+**/*.test
+**/*.out
+**/*.tmp
+
+# Local databases and secrets. The image carries a source archive of the whole
+# build context, so these would otherwise ship inside it.
+**/*.db
+**/*.db-journal
+**/*.db-wal
+**/.env
+
+# A local Go workspace points at directories outside the build context.
+/go.work
+/go.work.sum
+
+**/.DS_Store

.editorconfig

@@ -0,0 +1,12 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 4
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[Makefile]
+indent_style = tab

.gitea/workflows/check.yml

@@ -0,0 +1,9 @@
+name: check
+on: [push]
+jobs:
+    check:
+        runs-on: ubuntu-latest
+        steps:
+            # actions/checkout v4.2.2, 2026-02-28
+            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+            - run: script/cibuild

Dockerfile

@@ -1,5 +1,22 @@
+# Lint stage — fast feedback on formatting and lint issues.
+# The golangci-lint image bundles Go, gcc and make, so it can run go vet on
+# the CGO sqlite package and golangci-lint without extra installs.
+# golangci/golangci-lint:v2.7.2 (Go 1.25.5), 2026-09-21
+FROM golangci/golangci-lint@sha256:5d6d5c70a61f1356adfd9dd6316ce286799fefc9d743421356ff1b00842368ba AS lint
+
+WORKDIR /src
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+
+RUN make fmt-check
+RUN make lint
+
 # Build stage
-FROM golang:1.24-bookworm AS builder
+# golang:1.24-bookworm, 2026-09-21
+FROM golang@sha256:1a6d4452c65dea36aac2e2d606b01b4a029ec90cc1ae53890540ce6173ea77ac AS builder
 
 # Install build dependencies (zstd for archive, gcc for CGO/sqlite3)
 RUN apt-get update && apt-get install -y --no-install-recommends \
@@ -10,14 +27,36 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 
 WORKDIR /src
 
+# Force BuildKit to run the lint stage before compiling or testing.
+COPY --from=lint /src/go.sum /dev/null
+
 # Copy everything
 COPY . .
 
 # Vendor dependencies (must be after copying source)
 RUN go mod download && go mod vendor
 
-# Build the binary with CGO enabled (required for sqlite3)
-RUN CGO_ENABLED=1 GOOS=linux go build -o /routewatch ./cmd/routewatch
+# Run the test suite in the build stage: -race needs cgo and the C compiler
+# installed above. The suite is offline (the live-feed test is opt-in).
+RUN make test
+
+# Build the binary with CGO enabled (required for sqlite3). The version the
+# page footer shows is the VERSION build argument when one is given, otherwise
+# `git describe --tags --always` of the .git in the build context (git comes
+# with this image): the tag on a tagged commit, tag-N-gHASH after one, the
+# short commit when no tag is reachable. A context that carries .git and still
+# yields no version fails the build. The footer links to the full commit.
+ARG VERSION
+RUN version="${VERSION:-$(git describe --tags --always || echo unknown)}"; \
+    if [ -e .git ] && { [ -z "$version" ] || [ "$version" = dev ] || \
+        [ "$version" = unknown ]; }; then \
+        echo "no version could be derived although the build context carries .git" >&2; \
+        exit 1; \
+    fi; \
+    CGO_ENABLED=1 GOOS=linux go build -o /routewatch -ldflags "\
+        -X git.eeqj.de/sneak/routewatch/internal/version.GitRevision=$(git rev-parse --verify HEAD || echo unknown) \
+        -X git.eeqj.de/sneak/routewatch/internal/version.GitRevisionShort=$version" \
+        ./cmd/routewatch
 
 # Create source archive with vendored dependencies
 RUN tar --zstd -cf /routewatch-source.tar.zst \
@@ -26,7 +65,8 @@ RUN tar --zstd -cf /routewatch-source.tar.zst \
     .
 
 # Runtime stage
-FROM debian:bookworm-slim
+# debian:bookworm-slim, 2026-09-21
+FROM debian@sha256:3783cc01769c7b2b1b83a5c5ad96c815348e28ed7da68e2e3687004faa906251
 
 # Install runtime dependencies
 # - ca-certificates: for HTTPS connections
@@ -53,13 +93,26 @@ RUN chown -R routewatch:routewatch /app
 
 ENV XDG_DATA_HOME=/var/lib
 
+# Cap the Go heap at 1.5 GiB so the runtime collects harder before the
+# container's memory limit is reached. setpriv in the entrypoint preserves this
+# the way it does XDG_DATA_HOME above.
+ENV GOMEMLIMIT=1536MiB
+
+# Cap glibc's malloc arenas. The SQLite C library allocates and frees millions
+# of small page-cache chunks from many threads; glibc otherwise creates up to
+# eight arenas per core (hundreds on a large host) and keeps each arena's freed
+# chunks resident, so process RSS climbs far above SQLite's live heap and never
+# comes back down. Two arenas keep that retained memory bounded; database writes
+# are already serialized, so the lost allocator concurrency costs nothing here.
+ENV MALLOC_ARENA_MAX=2
+
 # Expose HTTP port
 EXPOSE 8080
 
 COPY ./entrypoint.sh /entrypoint.sh
 
-# Health check using the health endpoint
+# Health check using the health endpoint, on the port PORT names
 HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
-    CMD curl -sf http://localhost:8080/.well-known/healthcheck.json || exit 1
+    CMD curl -sf "http://localhost:${PORT:-8080}/.well-known/healthcheck.json" || exit 1
 
 ENTRYPOINT ["/bin/bash", "/entrypoint.sh" ]

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Jeffrey Paul <sneak@sneak.berlin>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

@@ -2,7 +2,7 @@ export DEBUG = routewatch
 
 # Git revision for version embedding
 GIT_REVISION := $(shell git rev-parse HEAD 2>/dev/null || echo "unknown")
-GIT_REVISION_SHORT := $(shell git rev-parse --short HEAD 2>/dev/null || echo "unknown")
+GIT_REVISION_SHORT := $(shell git describe --tags --always 2>/dev/null || echo "unknown")
 VERSION_PKG := git.eeqj.de/sneak/routewatch/internal/version
 LDFLAGS := -X $(VERSION_PKG).GitRevision=$(GIT_REVISION) -X $(VERSION_PKG).GitRevisionShort=$(GIT_REVISION_SHORT)
 

README.md

@@ -1,6 +1,9 @@
 # RouteWatch
 
-RouteWatch is a real-time BGP routing table monitor that streams BGP UPDATE messages from the RIPE RIS Live service, maintains a live routing table in SQLite, and provides HTTP APIs for querying routing information.
+RouteWatch is an MIT-licensed Go daemon by @sneak that monitors the BGP routing
+table in real time: it streams BGP UPDATE messages from the RIPE RIS Live
+service, maintains a live routing table in SQLite, and provides HTTP APIs for
+querying routing information.
 
 
 ## Features
@@ -125,7 +128,10 @@ routewatch/
 4. **Handler Details**
    - **ASHandler**: Tracks all ASNs seen in AS paths
    - **PeerHandler**: Records BGP peer information
-   - **PrefixHandler**: Maintains live routing table (upserts on announcement, deletes on withdrawal)
+   - **PrefixHandler**: Maintains live routing table (upserts on announcement, deletes on withdrawal,
+     deletes all of a peer's routes when its BGP session goes down). Routes are kept per peer IP, so
+     when one peer IP has sessions on two collectors, a session going down on one also removes the
+     routes the other still carries, until they are announced again.
    - **PeeringHandler**: Extracts AS peering relationships from AS paths
 
 5. **HTTP Request Flow**
@@ -138,8 +144,15 @@ routewatch/
 - **Batched Writes**: All database operations are batched for performance
 - **Backpressure**: Probabilistic message dropping when queues exceed 50% capacity
 - **Graceful Shutdown**: 60-second timeout, flushes all pending batches
-- **Reconnection**: Exponential backoff (5s-320s) with reset after 30s of stable connection
-- **IPv4 Optimization**: IP ranges stored as uint32 for O(1) lookups
+- **Reconnection**: Any end of the stream other than shutdown, including RIS Live
+  ending the response normally, marks the feed disconnected and reconnects with
+  exponential backoff (5s-320s). The backoff resets after a stream that lasted
+  more than 30s. A stream with no line for 60s is dropped and reconnected.
+- **IP Lookup**: the most specific live route is found by looking up the
+  address's prefix at each mask length, longest first, in the prefix index
+  (at most 25 lookups for IPv4, 113 for IPv6); prefixes are stored in the
+  text form Go's `net/netip` prints. Routes shorter than /8 for IPv4 or /16
+  for IPv6, such as a default route, are not used.
 
 ### Database Schema
 
@@ -151,7 +164,7 @@ prefixes_v6(id, prefix, mask_length, first_seen, last_seen)
 
 -- Live routing tables (one per IP version)
 live_routes_v4(id, prefix, mask_length, origin_asn, peer_ip, as_path,
-               next_hop, last_updated, v4_ip_start, v4_ip_end)
+               next_hop, last_updated)
 live_routes_v6(id, prefix, mask_length, origin_asn, peer_ip, as_path,
                next_hop, last_updated)
 
@@ -165,13 +178,92 @@ bgp_peers(id, peer_ip, peer_asn, last_message_type, last_seen)
 Configuration is handled via environment variables and OS-specific paths:
 
 | Variable | Default | Description |
-|----------|---------|-------------|
-| `PORT` | `8080` | HTTP server port |
+|----------|----------|-------------|
+| `PORT` | `8080` | HTTP server port, a whole number from 1 to 65535 |
 | `DEBUG` | (empty) | Set to `routewatch` for debug logging |
+| `XDG_DATA_HOME` | `/var/lib` (in the Docker image) | Base of the state directory; must be an absolute path |
+| `GOMEMLIMIT` | `1536MiB` (in the Docker image) | Go soft memory limit; see Memory |
+| `MALLOC_ARENA_MAX` | `2` (in the Docker image) | glibc malloc arena cap, a positive whole number; see Memory |
+
+A variable that is set to an invalid value stops the start with an error and a
+non-zero exit. An empty variable counts as unset.
 
 State directory (database location):
 - macOS: `~/Library/Application Support/routewatch/`
-- Linux: `/var/lib/routewatch/` or `~/.local/share/routewatch/`
+- Linux: `/var/lib/berlin.sneak.app.routewatch/` when running as root,
+  otherwise `$XDG_DATA_HOME/berlin.sneak.app.routewatch/` (with `XDG_DATA_HOME`
+  unset, `~/.local/share/berlin.sneak.app.routewatch/`). In the Docker image
+  this is `/var/lib/berlin.sneak.app.routewatch/`.
+
+## Memory
+
+The daemon holds a live routing table, so its memory grows with the size of the
+data it tracks. The image sets ceilings that keep it inside a 5 GiB container.
+
+Budget:
+- Go heap: a 1.5 GiB soft limit (`GOMEMLIMIT=1536MiB`, set in the image).
+- SQLite: at most 640 MiB of page cache across the connection pool (64 MiB per
+  connection, 10 connections) and a 1.5 GiB hard heap limit for the C library.
+- glibc allocator: the SQLite C library runs on glibc `malloc`, which frees
+  page-cache chunks back to per-arena free lists rather than to the kernel, so
+  process RSS tracks the high-water mark of those arenas, not SQLite's live
+  heap. glibc creates up to eight arenas per core, so on a many-core host the
+  retained memory — and thus RSS — grows with the core count. The image sets
+  `MALLOC_ARENA_MAX=2` to bound it; the two-arena cap costs nothing here because
+  database writes are already serialized.
+- About 0.2 GiB for everything else in the runtime.
+
+Run the container with a memory limit of 5 GiB and swap disabled:
+
+```bash
+docker run --memory=5g --memory-swap=5g ...
+```
+
+or the equivalent in your deployment tool. This leaves headroom above the
+ceilings for spikes and the kernel page cache.
+
+Override the Go soft limit by setting `GOMEMLIMIT` in the environment (for
+example `-e GOMEMLIMIT=1GiB`); this replaces the image default. `MALLOC_ARENA_MAX`
+can be overridden the same way, but raising it lets RSS climb again on a
+many-core host.
+
+What happens at each limit:
+- Go soft limit: as the heap approaches `GOMEMLIMIT`, the runtime runs garbage
+  collection more aggressively rather than growing further.
+- SQLite: at a 1 GiB soft heap limit it recycles its page cache instead of
+  allocating more; at the 1.5 GiB hard heap limit a statement fails with an
+  out-of-memory error, and the handler logs it and drops that batch. The process
+  keeps running.
+- Handler queues: each of the four handler queues holds at most 20,000 messages.
+  When a queue fills, the streamer drops messages instead of blocking.
+- Handler batches: while the AS, peer or prefix handler writes a batch to the
+  database, the updates that arrive collect in its next batch, which stops at
+  ten times the batch size: 300,000 updates for the AS handler
+  (`asnBatchMaxSize`, about 10 MiB), 100,000 for the peer handler
+  (`peerBatchMaxSize`, about 10 MiB) and 250,000 for the prefix handler
+  (`prefixBatchMaxSize`, about 60 MiB). At that size the handler takes nothing
+  more off its queue until the write ends, so the queue fills and the streamer
+  drops messages as above. With the batches being written, the three handlers'
+  batches take at most about 0.25 GiB of the Go heap's 1.5 GiB.
+
+With `DEBUG=routewatch` the daemon logs a `System stats` line every 60 seconds
+with the goroutine count and Go memory figures.
+
+## Running under upaas
+
+What the [upaas](https://git.eeqj.de/sneak/upaas) app needs:
+
+- Container port: `8080`.
+- Volume: one, at container path `/var/lib/berlin.sneak.app.routewatch`.
+- Environment: nothing is required. Leave `XDG_DATA_HOME`, `GOMEMLIMIT` and
+  `MALLOC_ARENA_MAX` at the image's values. `DEBUG=routewatch` is optional and
+  adds the `System stats` memory line to the log.
+- Memory Limit: `5g`, the 5 GiB limit from Memory above. upaas sets no swap
+  limit, so on a host with swap Docker allows the same amount of swap again.
+- Health check: the image's `HEALTHCHECK` requests
+  `/.well-known/healthcheck.json` on the container port. upaas reads the
+  container's health 60 seconds after a deploy and fails the deploy unless it
+  is `healthy`.
 
 ## Development
 
@@ -204,7 +296,9 @@ them. We provide:
 - `script/projectname` — print the project name (used for the Docker
   image tag)
 - `script/test` — run the test suite
-  (`go test -timeout 30s -race -cover ./...`, verbose rerun on failure)
+  (`go test -short -timeout 30s -race -cover ./...`, verbose rerun on
+  failure). The `-short` flag skips the live-network integration test so the
+  default run is deterministic and offline.
 - `script/lint` — run `go vet ./...` and `golangci-lint run`
 - `script/fmt` — format all code (writes)
 - `script/fmt-check` — check formatting (read-only)
@@ -218,6 +312,15 @@ them. We provide:
 - `script/install-precommit` — install the git pre-commit hook that
   runs `script/precommit`
 
+The live-network integration test `TestRouteWatchLiveFeed` streams the RIPE
+RIS feed for a few seconds and is skipped in short mode. To run it on demand,
+invoke `go test` directly without `-short`:
+`go test -run TestRouteWatchLiveFeed ./internal/routewatch/`.
+
 ## License
 
-See LICENSE file.
+MIT. See [`LICENSE`](LICENSE).
+
+## Author
+
+[@sneak](https://sneak.berlin)

TODO.md

@@ -10,19 +10,95 @@
 
 # Status
 
-pre-1.0. No git tags. Runs in production-style Docker deployment, but
-the policy compliance branch (repo-policies-compliance, make check
-passing, clean tree) is unmerged to main and the CI workflow is missing.
+pre-1.0. No git tags. The Docker build runs the format check, the linter
+and the tests, and the Gitea workflow runs that build on every push. The
+image sets memory ceilings for a 5 GiB container (README "Memory") and the
+README says how to run it under upaas (README "Running under upaas"). A
+35-hour run of `3898daa` on the live feed peaked at about 1 GiB, without a
+container memory limit.
 
 # Next Step
 
-Merge repo-policies-compliance into main (3 commits: policy files and
-.gitignore, Makefile targets fmt-check/check/docker/hooks, gofmt pass),
-then add .gitea/workflows/check.yml as a small follow-up commit so CI
-runs make check on main.
+`next` waits for sneak to merge it to `main` through
+https://git.eeqj.de/sneak/routewatch/pulls/6. After that, setting
+routewatch up under upaas on fsn1app1 and deploying it are his
+(https://git.eeqj.de/sneak/routewatch/issues/31), and so is the run under a
+real 5 GiB limit (https://git.eeqj.de/sneak/routewatch/issues/3).
 
 # Completed Steps
 
+- 2026-10-03: `/api/v1/stats` serves the prefix distribution from memory,
+  seeded at startup and adjusted on every live-route write, so a request no
+  longer reads every live route (closes #30)
+- 2026-10-03: a new database is created with `auto_vacuum` set to
+  incremental, through the connection string so it is set before the file
+  is first written, and each periodic incremental vacuum now returns up to
+  1000 free pages; the late `PRAGMA auto_vacuum` in `Initialize`, which
+  SQLite ignored, is gone (closes #43)
+- 2026-10-03: looking up an IP address no longer reads every IPv6 route:
+  both families find the most specific live route with at most 33 or 129
+  lookups on the prefix index, and the IPv4 range columns are gone. Prefixes
+  from the feed are stored in one text form, so an IPv6 withdrawal, which the
+  feed sends uncompressed, now removes its route (closes #48)
+- 2026-10-02: a plain `docker build .` stamps the commit's tag or short
+  commit (`git describe --tags --always`) into the page footer instead of
+  `unknown`: `.dockerignore` sends `.git` without `.git/config`, a `VERSION`
+  build argument takes precedence, and `make build` stamps the same value
+  (closes #46)
+- 2026-09-29: the entrypoint creates the data directory if it is missing and
+  stops the start if a step fails; README "Running under upaas" no longer
+  asks for the host directory to be created first (closes #42)
+- 2026-09-29: `.dockerignore` keeps `.git`, local build output, local
+  databases and `.env` out of the Docker build context, and so out of the
+  source archive in the image (closes #39)
+- 2026-09-29: README first line names the MIT license and the author;
+  the License section now says MIT and links `LICENSE`, and an Author
+  section was added; this file brought up to date (closes #38)
+- 2026-09-29: MIT `LICENSE` (closes #1)
+- 2026-09-28: stopping the daemon while the feed is flowing no longer
+  panics with "send on closed channel": the read loop checks for a stop
+  just before handing a message to the handler queues, and a second
+  `Stop` no longer closes the queues again (closes #34)
+- 2026-09-28: `docker stop` no longer kills the daemon 2 seconds after the
+  stop signal: the entrypoint switches to the `routewatch` user with
+  `setpriv` instead of `runuser`, so the daemon receives the signal itself
+  and gets the whole wait `docker stop` allows, up to its own 60-second
+  limit (closes #33)
+- 2026-09-28: ready to run under upaas: a set but invalid `PORT`,
+  `XDG_DATA_HOME` or `MALLOC_ARENA_MAX` stops the start, the health
+  check follows `PORT`, README "Running under upaas" section (closes
+  #31)
+- 2026-09-22: realtime in-memory database statistics: counts seeded at
+  startup and adjusted on every write, oldest/newest route timestamps via
+  index-end lookups; `/api/v1/stats` no longer scans the tables (closes
+  #27)
+- 2026-09-21: batch writes take the write lock when their transaction
+  begins (`_txlock=immediate`), so they wait out a WAL checkpoint instead
+  of failing with "database is locked" (closes #25)
+- 2026-09-21: `MALLOC_ARENA_MAX=2` in the image caps glibc malloc arenas,
+  so memory outside the Go runtime no longer grows with the core count
+  (closes #23)
+- 2026-09-21: `GOMEMLIMIT=1536MiB` in the image; README Memory section
+  with the memory budget and the 5 GiB container limit (closes #13)
+- 2026-09-21: the four handler queues hold at most 20,000 messages each,
+  down from 100,000 (closes #11)
+- 2026-09-21: two goroutine leaks fixed: the stats handlers after a
+  timeout and the streamer's tickers on every reconnect (closes #12)
+- 2026-09-21: parsed RIS messages no longer keep the unused `Community`
+  and `Raw` fields (closes #9)
+- 2026-09-21: `.editorconfig`, and a Gitea workflow that runs
+  `script/cibuild` on every push (closes #14)
+- 2026-09-21: the peering handler's AS-path map holds at most 500,000
+  paths and is swapped for an empty one every 30 seconds instead of copied
+  (closes #10)
+- 2026-09-21: SQLite memory bounded across the whole connection pool: a
+  64 MiB page cache on each connection, 1 GiB soft and 1.5 GiB hard heap
+  limits (closes #8)
+- 2026-09-21: the Docker build runs the format check, the linter and the
+  tests, linting in a separate stage on a golangci-lint image pinned by
+  digest (closes #5)
+- 2026-09-21: `make test` skips the live-network feed test (`-short`), so
+  `make check` no longer depends on the network (closes #2)
 - 2026-07-07 Adopted scripts-to-rule-them-all: `script/` entrypoints,
   Makefile shims, README Entrypoints section
 - 2026-02-22: repo policy compliance: required policy files, .gitignore
@@ -41,8 +117,6 @@ runs make check on main.
 
 # Future Steps
 
-- Verify main is green after the merge: make check locally and the new
-  CI workflow passing
-- Review stale remote branches fix-min-time-calculation and
-  optimize-sqlite-settings: land or delete
-- Clean up the tmp/ directory at the repo root: gitignore or remove
+- Production memory under 5 GiB: whether to test under a real 5 GiB
+  container limit on fsn1app1 is open for sneak
+  (https://git.eeqj.de/sneak/routewatch/issues/3)

entrypoint.sh

@@ -1,7 +1,20 @@
 #!/bin/bash
+set -euo pipefail
 
+# glibc silently ignores a malformed MALLOC_ARENA_MAX, so refuse it here.
+if [[ -n "${MALLOC_ARENA_MAX:-}" && ! "$MALLOC_ARENA_MAX" =~ ^[1-9][0-9]*$ ]]; then
+    echo "MALLOC_ARENA_MAX must be a positive whole number, got '$MALLOC_ARENA_MAX'" >&2
+    exit 1
+fi
+
+# Give the data directory to the routewatch user before the daemon starts,
+# whether it is missing, an empty root-owned mount, or holds another uid's files.
+mkdir -p /var/lib/berlin.sneak.app.routewatch
 cd /var/lib/berlin.sneak.app.routewatch
 chown -R routewatch:routewatch .
 chmod 700 .
 
-exec runuser -u routewatch -- /app/routewatch
+# setpriv replaces itself with the daemon, so the daemon receives the stop
+# signal directly. runuser would stay in between and kill the daemon 2 seconds
+# after passing the signal on.
+exec setpriv --reuid=routewatch --regid=routewatch --init-groups -- /app/routewatch

internal/config/config.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strconv"
 	"time"
 )
 
@@ -18,6 +19,12 @@ const (
 
 	// defaultRouteExpirationMinutes is the default route expiration timeout in minutes
 	defaultRouteExpirationMinutes = 5
+
+	// defaultPort is the HTTP port used when PORT is not set
+	defaultPort = 8080
+
+	// maxPort is the highest TCP port number
+	maxPort = 65535
 )
 
 // Config holds configuration for the entire application
@@ -25,6 +32,9 @@ type Config struct {
 	// StateDir is the directory for all application state (database, snapshots)
 	StateDir string
 
+	// Port is the TCP port the HTTP server listens on
+	Port int
+
 	// MaxRuntime is the maximum runtime (0 = run forever)
 	MaxRuntime time.Duration
 
@@ -43,8 +53,14 @@ func New() (*Config, error) {
 		return nil, fmt.Errorf("failed to determine state directory: %w", err)
 	}
 
+	port, err := getPort()
+	if err != nil {
+		return nil, err
+	}
+
 	return &Config{
 		StateDir:                    stateDir,
+		Port:                        port,
 		MaxRuntime:                  0,                                           // Run forever by default
 		EnableBatchedDatabaseWrites: true,                                        // Enable batching by default
 		RouteExpirationTimeout:      defaultRouteExpirationMinutes * time.Minute, // For active route monitoring
@@ -69,13 +85,20 @@ func getStateDirectory() (string, error) {
 		return filepath.Join(home, "Library", "Application Support", AppIdentifier), nil
 
 	case "linux", "freebsd", "openbsd", "netbsd":
+		// The XDG spec requires an absolute path; a relative one would put
+		// the database somewhere unexpected.
+		xdgData := os.Getenv("XDG_DATA_HOME")
+		if xdgData != "" && !filepath.IsAbs(xdgData) {
+			return "", fmt.Errorf("XDG_DATA_HOME must be an absolute path, got %q", xdgData)
+		}
+
 		// Unix-like: /var/lib/berlin.sneak.app.routewatch if root, else XDG_DATA_HOME
 		if os.Geteuid() == 0 {
 			return filepath.Join("/var/lib", AppIdentifier), nil
 		}
 
 		// Check XDG_DATA_HOME first
-		if xdgData := os.Getenv("XDG_DATA_HOME"); xdgData != "" {
+		if xdgData != "" {
 			return filepath.Join(xdgData, AppIdentifier), nil
 		}
 
@@ -92,6 +115,22 @@ func getStateDirectory() (string, error) {
 	}
 }
 
+// getPort returns the HTTP port from PORT, or defaultPort when PORT is not set
+func getPort() (int, error) {
+	value := os.Getenv("PORT")
+	if value == "" {
+		return defaultPort, nil
+	}
+
+	// ParseUint, unlike Atoi, refuses a sign: the health check URL cannot use "+9090"
+	port, err := strconv.ParseUint(value, 10, 0)
+	if err != nil || port < 1 || port > maxPort {
+		return 0, fmt.Errorf("PORT must be a whole number from 1 to %d, got %q", maxPort, value)
+	}
+
+	return int(port), nil
+}
+
 // EnsureDirectories creates all necessary directories if they don't exist
 func (c *Config) EnsureDirectories() error {
 	// Ensure state directory exists

internal/config/config_test.go

@@ -0,0 +1,62 @@
+package config
+
+import (
+	"runtime"
+	"testing"
+)
+
+func TestNewReadsPort(t *testing.T) {
+	tests := map[string]int{
+		"":      defaultPort,
+		"1":     1,
+		"9090":  9090,
+		"65535": 65535,
+	}
+
+	for value, want := range tests {
+		t.Run(value, func(t *testing.T) {
+			t.Setenv("PORT", value)
+			t.Setenv("XDG_DATA_HOME", "")
+
+			cfg, err := New()
+			if err != nil {
+				t.Fatalf("New() with PORT=%q: %v", value, err)
+			}
+
+			if cfg.Port != want {
+				t.Errorf("New() with PORT=%q: Port = %d, want %d", value, cfg.Port, want)
+			}
+		})
+	}
+}
+
+func TestNewRefusesInvalidPort(t *testing.T) {
+	for _, value := range []string{"0", "65536", "-1", "+9090", "http", "80.5"} {
+		t.Run(value, func(t *testing.T) {
+			t.Setenv("PORT", value)
+			t.Setenv("XDG_DATA_HOME", "")
+
+			if _, err := New(); err == nil {
+				t.Errorf("New() with PORT=%q returned no error", value)
+			}
+		})
+	}
+}
+
+func TestNewRefusesRelativeXDGDataHome(t *testing.T) {
+	if runtime.GOOS == "darwin" {
+		t.Skip("macOS does not read XDG_DATA_HOME")
+	}
+
+	t.Setenv("PORT", "")
+
+	t.Setenv("XDG_DATA_HOME", "relative/path")
+	if _, err := New(); err == nil {
+		t.Error("New() with a relative XDG_DATA_HOME returned no error")
+	}
+
+	t.Setenv("XDG_DATA_HOME", "/var/lib")
+	if _, err := New(); err != nil {
+		t.Errorf("New() with XDG_DATA_HOME=/var/lib: %v", err)
+	}
+}

internal/database/counts.go

@@ -0,0 +1,203 @@
+package database
+
+import (
+	"context"
+	"fmt"
+	"sync"
+)
+
+// liveCounts holds the running row counts and the prefix distribution that the
+// stats endpoints report. They are seeded once at startup from the tables and
+// then adjusted on every write, so a stats read serves them from memory instead
+// of running a query over the tables. The COUNT(*) scans (issue 27) and then
+// the prefix distribution query (issue 30) each grew with the database until
+// they took the whole request timeout and made /api/v1/stats return 500.
+//
+// A single mutex guards all fields so the stats reader takes a consistent
+// snapshot at one instant and writers, which already run under the database
+// write lock, adjust the counts after their transaction commits.
+type liveCounts struct {
+	mu         sync.RWMutex
+	asns       int
+	prefixesV4 int
+	prefixesV6 int
+	peerings   int
+	peers      int
+	routesV4   int
+	routesV6   int
+	// The prefix distribution: for each mask length, the number of distinct
+	// prefixes that have at least one live route.
+	distributionV4 [ipv4Bits + 1]int
+	distributionV6 [ipv6Bits + 1]int
+}
+
+// seed sets every count to the value read from the tables at startup. It runs
+// before any writer, so it needs no coordination with the adjust methods.
+func (c *liveCounts) seed(asns, prefixesV4, prefixesV6, peerings, peers, routesV4, routesV6 int,
+	distributionV4, distributionV6 []PrefixDistribution) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.asns = asns
+	c.prefixesV4 = prefixesV4
+	c.prefixesV6 = prefixesV6
+	c.peerings = peerings
+	c.peers = peers
+	c.routesV4 = routesV4
+	c.routesV6 = routesV6
+	for _, entry := range distributionV4 {
+		addAtMaskLength(c.distributionV4[:], entry.MaskLength, entry.Count)
+	}
+	for _, entry := range distributionV6 {
+		addAtMaskLength(c.distributionV6[:], entry.MaskLength, entry.Count)
+	}
+}
+
+// addASNs adds n to the ASN count.
+func (c *liveCounts) addASNs(n int) {
+	c.mu.Lock()
+	c.asns += n
+	c.mu.Unlock()
+}
+
+// addPrefixes adds to the IPv4 and IPv6 prefix counts.
+func (c *liveCounts) addPrefixes(v4, v6 int) {
+	c.mu.Lock()
+	c.prefixesV4 += v4
+	c.prefixesV6 += v6
+	c.mu.Unlock()
+}
+
+// addPeerings adds n to the peering count.
+func (c *liveCounts) addPeerings(n int) {
+	c.mu.Lock()
+	c.peerings += n
+	c.mu.Unlock()
+}
+
+// addPeers adds n to the BGP peer count.
+func (c *liveCounts) addPeers(n int) {
+	c.mu.Lock()
+	c.peers += n
+	c.mu.Unlock()
+}
+
+// addRoutes adds to the IPv4 and IPv6 live-route counts. Deletions pass
+// negative values.
+func (c *liveCounts) addRoutes(v4, v6 int) {
+	c.mu.Lock()
+	c.routesV4 += v4
+	c.routesV6 += v6
+	c.mu.Unlock()
+}
+
+// addToDistribution adds n to the IPv4 and IPv6 prefix distributions once for
+// each listed mask length. A write lists the mask lengths of the prefixes it
+// gave their first live route with n = 1, and of the prefixes it left with no
+// live route with n = -1.
+func (c *liveCounts) addToDistribution(maskLengthsV4, maskLengthsV6 []int, n int) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	for _, maskLength := range maskLengthsV4 {
+		addAtMaskLength(c.distributionV4[:], maskLength, n)
+	}
+	for _, maskLength := range maskLengthsV6 {
+		addAtMaskLength(c.distributionV6[:], maskLength, n)
+	}
+}
+
+// addAtMaskLength adds n to counts[maskLength]. A mask length the array has no
+// entry for is ignored, so a malformed route cannot crash the daemon.
+func addAtMaskLength(counts []int, maskLength, n int) {
+	if maskLength >= 0 && maskLength < len(counts) {
+		counts[maskLength] += n
+	}
+}
+
+// fill copies the counts into a Stats, including the derived totals, under a
+// single read lock so the reader sees one consistent snapshot.
+func (c *liveCounts) fill(s *Stats) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	s.ASNs = c.asns
+	s.IPv4Prefixes = c.prefixesV4
+	s.IPv6Prefixes = c.prefixesV6
+	s.Prefixes = c.prefixesV4 + c.prefixesV6
+	s.Peerings = c.peerings
+	s.Peers = c.peers
+	s.IPv4Routes = c.routesV4
+	s.IPv6Routes = c.routesV6
+	s.LiveRoutes = c.routesV4 + c.routesV6
+	s.IPv4PrefixDistribution = distributionList(c.distributionV4[:])
+	s.IPv6PrefixDistribution = distributionList(c.distributionV6[:])
+}
+
+// distributionList lists the mask lengths that have at least one prefix, in
+// ascending order, the way the distribution query returns them.
+func distributionList(counts []int) []PrefixDistribution {
+	var list []PrefixDistribution
+	for maskLength, count := range counts {
+		if count > 0 {
+			list = append(list, PrefixDistribution{MaskLength: maskLength, Count: count})
+		}
+	}
+
+	return list
+}
+
+// countRows returns the number of rows in the named table. It is used only at
+// startup to seed the in-memory counters, so a full COUNT(*) is acceptable.
+func (d *Database) countRows(ctx context.Context, table string) (int, error) {
+	var n int
+	// table is one of a fixed set of literals below, never external input.
+	if err := d.db.QueryRowContext(ctx, "SELECT COUNT(*) FROM "+table).Scan(&n); err != nil {
+		return 0, fmt.Errorf("failed to count %s: %w", table, err)
+	}
+
+	return n, nil
+}
+
+// seedCounts reads the current row counts and prefix distribution from the
+// tables into the in-memory counters. It runs once at startup, before the
+// streamer begins writing.
+func (d *Database) seedCounts(ctx context.Context) error {
+	asns, err := d.countRows(ctx, "asns")
+	if err != nil {
+		return err
+	}
+	prefixesV4, err := d.countRows(ctx, "prefixes_v4")
+	if err != nil {
+		return err
+	}
+	prefixesV6, err := d.countRows(ctx, "prefixes_v6")
+	if err != nil {
+		return err
+	}
+	peerings, err := d.countRows(ctx, "peerings")
+	if err != nil {
+		return err
+	}
+	peers, err := d.countRows(ctx, "bgp_peers")
+	if err != nil {
+		return err
+	}
+	routesV4, err := d.countRows(ctx, "live_routes_v4")
+	if err != nil {
+		return err
+	}
+	routesV6, err := d.countRows(ctx, "live_routes_v6")
+	if err != nil {
+		return err
+	}
+	distributionV4, distributionV6, err := d.GetPrefixDistributionContext(ctx)
+	if err != nil {
+		return err
+	}
+
+	d.counts.seed(asns, prefixesV4, prefixesV6, peerings, peers, routesV4, routesV6,
+		distributionV4, distributionV6)
+
+	return nil
+}

internal/database/counts_test.go

@@ -0,0 +1,592 @@
+package database
+
+import (
+	"context"
+	"slices"
+	"sync"
+	"testing"
+	"time"
+
+	"git.eeqj.de/sneak/routewatch/internal/config"
+	"git.eeqj.de/sneak/routewatch/internal/logger"
+	"github.com/google/uuid"
+)
+
+// mkV4Route builds an IPv4 live route with its mask length taken from the
+// prefix.
+func mkV4Route(t *testing.T, prefix string, asn int, ts time.Time) *LiveRoute {
+	t.Helper()
+
+	maskLength, err := prefixMaskLength(prefix)
+	if err != nil {
+		t.Fatalf("prefixMaskLength(%s): %v", prefix, err)
+	}
+
+	return &LiveRoute{
+		ID:          uuid.New(),
+		Prefix:      prefix,
+		MaskLength:  maskLength,
+		IPVersion:   ipVersionV4,
+		OriginASN:   asn,
+		PeerIP:      "192.0.2.1",
+		ASPath:      []int{asn},
+		NextHop:     "192.0.2.254",
+		LastUpdated: ts,
+	}
+}
+
+// mkV6Route builds an IPv6 live route.
+func mkV6Route(prefix string, asn int, ts time.Time) *LiveRoute {
+	return &LiveRoute{
+		ID:          uuid.New(),
+		Prefix:      prefix,
+		MaskLength:  32,
+		IPVersion:   ipVersionV6,
+		OriginASN:   asn,
+		PeerIP:      "2001:db8::1",
+		ASPath:      []int{asn},
+		NextHop:     "2001:db8::ffff",
+		LastUpdated: ts,
+	}
+}
+
+// TestLiveCountsTrackWritesInRealtime checks that the stats counts start at
+// zero, reflect each write the moment it commits (no recompute, no timer), do
+// not move when a route is merely re-announced, and drop when a route is
+// deleted. These counts are what /api/v1/stats reports; before this change the
+// endpoint recomputed them with a COUNT(*) over each table on every request.
+func TestLiveCountsTrackWritesInRealtime(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ctx := context.Background()
+
+	empty, err := db.GetStatsContext(ctx)
+	if err != nil {
+		t.Fatalf("GetStatsContext on empty database: %v", err)
+	}
+	if empty.ASNs != 0 || empty.Prefixes != 0 || empty.Peerings != 0 ||
+		empty.Peers != 0 || empty.LiveRoutes != 0 {
+		t.Fatalf("empty database counts nonzero: %+v", empty)
+	}
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+
+	if err := db.GetOrCreateASNBatch(map[int]time.Time{64500: ts, 64501: ts}); err != nil {
+		t.Fatalf("GetOrCreateASNBatch: %v", err)
+	}
+	if err := db.UpdatePrefixesBatch(map[string]time.Time{
+		"198.51.100.0/24": ts,
+		"2001:db8::/32":   ts,
+	}); err != nil {
+		t.Fatalf("UpdatePrefixesBatch: %v", err)
+	}
+	if err := db.UpdatePeerBatch(map[string]PeerUpdate{
+		"192.0.2.1": {PeerIP: "192.0.2.1", PeerASN: 64500, MessageType: "UPDATE", Timestamp: ts},
+	}); err != nil {
+		t.Fatalf("UpdatePeerBatch: %v", err)
+	}
+	if err := db.RecordPeering(64500, 64501, ts); err != nil {
+		t.Fatalf("RecordPeering: %v", err)
+	}
+
+	routes := []*LiveRoute{
+		mkV4Route(t, "198.51.100.0/24", 64500, ts),
+		mkV4Route(t, "203.0.113.0/24", 64501, ts.Add(time.Minute)),
+		mkV6Route("2001:db8::/32", 64502, ts.Add(2*time.Minute)),
+	}
+	if err := db.UpsertLiveRouteBatch(routes); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+
+	stats, err := db.GetStatsContext(ctx)
+	if err != nil {
+		t.Fatalf("GetStatsContext: %v", err)
+	}
+	assertCounts(t, "after inserts", stats, wantCounts{
+		asns: 2, prefixes: 2, peerings: 1, peers: 1,
+		ipv4Routes: 2, ipv6Routes: 1, liveRoutes: 3,
+	})
+
+	// Re-announcing the same routes is an update, not an insert: counts hold.
+	if err := db.UpsertLiveRouteBatch(routes); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch (re-announce): %v", err)
+	}
+	stats, err = db.GetStatsContext(ctx)
+	if err != nil {
+		t.Fatalf("GetStatsContext: %v", err)
+	}
+	assertCounts(t, "after re-announce", stats, wantCounts{
+		asns: 2, prefixes: 2, peerings: 1, peers: 1,
+		ipv4Routes: 2, ipv6Routes: 1, liveRoutes: 3,
+	})
+
+	// A withdrawal removes one route.
+	if err := db.DeleteLiveRouteBatch([]LiveRouteDeletion{
+		{Prefix: "203.0.113.0/24", PeerIP: "192.0.2.1", IPVersion: ipVersionV4},
+	}); err != nil {
+		t.Fatalf("DeleteLiveRouteBatch: %v", err)
+	}
+	stats, err = db.GetStatsContext(ctx)
+	if err != nil {
+		t.Fatalf("GetStatsContext: %v", err)
+	}
+	assertCounts(t, "after delete", stats, wantCounts{
+		asns: 2, prefixes: 2, peerings: 1, peers: 1,
+		ipv4Routes: 1, ipv6Routes: 1, liveRoutes: 2,
+	})
+}
+
+// TestLiveCountsSeededFromDatabaseAtStartup writes rows, reopens the same
+// database file, and checks the counts and the prefix distribution come back
+// from the seed scan rather than starting at zero.
+func TestLiveCountsSeededFromDatabaseAtStartup(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	if err := db.GetOrCreateASNBatch(map[int]time.Time{64500: ts, 64501: ts, 64502: ts}); err != nil {
+		t.Fatalf("GetOrCreateASNBatch: %v", err)
+	}
+	if err := db.UpsertLiveRouteBatch([]*LiveRoute{
+		mkV4Route(t, "198.51.100.0/24", 64500, ts),
+		mkV6Route("2001:db8::/32", 64502, ts),
+	}); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+	if err := db.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+
+	reopened, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to reopen database: %v", err)
+	}
+	defer func() { _ = reopened.Close() }()
+
+	stats, err := reopened.GetStatsContext(context.Background())
+	if err != nil {
+		t.Fatalf("GetStatsContext after reopen: %v", err)
+	}
+	if stats.ASNs != 3 {
+		t.Errorf("seeded ASNs = %d, want 3", stats.ASNs)
+	}
+	if stats.IPv4Routes != 1 || stats.IPv6Routes != 1 || stats.LiveRoutes != 2 {
+		t.Errorf("seeded routes = (v4 %d, v6 %d, total %d), want (1, 1, 2)",
+			stats.IPv4Routes, stats.IPv6Routes, stats.LiveRoutes)
+	}
+	assertDistribution(t, "seeded IPv4 distribution", stats.IPv4PrefixDistribution,
+		[]PrefixDistribution{{MaskLength: 24, Count: 1}})
+	assertDistribution(t, "seeded IPv6 distribution", stats.IPv6PrefixDistribution,
+		[]PrefixDistribution{{MaskLength: 32, Count: 1}})
+}
+
+// TestPrefixDistributionTracksWrites checks that the prefix distribution the
+// stats read reports stays exact across each kind of live-route write, and that
+// after every step it equals what the distribution query reads from the route
+// tables. The steps run once through the batch methods the prefix handler uses
+// and once through the single-route methods.
+func TestPrefixDistributionTracksWrites(t *testing.T) {
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	shared := mkV4Route(t, "198.51.100.0/24", 64500, ts)
+	sharedSecondPeer := mkV4Route(t, "198.51.100.0/24", 64500, ts)
+	sharedSecondPeer.PeerIP = "192.0.2.2"
+	other := mkV4Route(t, "203.0.113.0/24", 64501, ts)
+	wide := mkV4Route(t, "172.16.0.0/16", 64502, ts)
+	v6 := mkV6Route("2001:db8::/32", 64503, ts)
+	v6SecondPeer := mkV6Route("2001:db8::/32", 64503, ts)
+	v6SecondPeer.PeerIP = "2001:db8::2"
+
+	all := []PrefixDistribution{{MaskLength: 16, Count: 1}, {MaskLength: 24, Count: 2}}
+	v6Only := []PrefixDistribution{{MaskLength: 32, Count: 1}}
+
+	steps := []struct {
+		name     string
+		announce []*LiveRoute
+		withdraw []*LiveRoute
+		wantV4   []PrefixDistribution
+		wantV6   []PrefixDistribution
+	}{
+		{
+			name:     "new routes",
+			announce: []*LiveRoute{shared, other, wide, v6},
+			wantV4:   all, wantV6: v6Only,
+		},
+		{
+			name:     "re-announcement",
+			announce: []*LiveRoute{shared, other, wide, v6},
+			wantV4:   all, wantV6: v6Only,
+		},
+		{
+			name:     "second peer announces a prefix that has a live route",
+			announce: []*LiveRoute{sharedSecondPeer, v6SecondPeer},
+			wantV4:   all, wantV6: v6Only,
+		},
+		{
+			name:     "withdrawal of a route that is not the last for its prefix",
+			withdraw: []*LiveRoute{shared, v6},
+			wantV4:   all, wantV6: v6Only,
+		},
+		{
+			name:     "withdrawal of the last route for a prefix",
+			withdraw: []*LiveRoute{sharedSecondPeer, v6SecondPeer},
+			wantV4:   []PrefixDistribution{{MaskLength: 16, Count: 1}, {MaskLength: 24, Count: 1}},
+		},
+		{
+			name:     "withdrawal of every remaining route",
+			withdraw: []*LiveRoute{other, wide},
+		},
+		{
+			name:     "two peers announce a new prefix together",
+			announce: []*LiveRoute{shared, sharedSecondPeer, v6, v6SecondPeer},
+			wantV4:   []PrefixDistribution{{MaskLength: 24, Count: 1}},
+			wantV6:   v6Only,
+		},
+		{
+			name:     "both routes for a prefix withdrawn together",
+			withdraw: []*LiveRoute{shared, sharedSecondPeer, v6, v6SecondPeer},
+		},
+		// The feed often withdraws a route that is not live. That must not take
+		// the prefix out of the distribution. A count wrongly taken below zero is
+		// left out of the answer, so the next step shows it: its announcement
+		// at the same mask length would then not be counted.
+		{
+			name:     "withdrawal of routes that are not live",
+			withdraw: []*LiveRoute{other, v6},
+		},
+		{
+			name:     "announcement after a withdrawal of routes that are not live",
+			announce: []*LiveRoute{other, v6},
+			wantV4:   []PrefixDistribution{{MaskLength: 24, Count: 1}},
+			wantV6:   v6Only,
+		},
+	}
+
+	for _, batch := range []bool{true, false} {
+		name := "single-route writes"
+		if batch {
+			name = "batch writes"
+		}
+
+		t.Run(name, func(t *testing.T) {
+			db, err := New(&config.Config{StateDir: t.TempDir()}, logger.New())
+			if err != nil {
+				t.Fatalf("failed to create database: %v", err)
+			}
+			defer func() { _ = db.Close() }()
+
+			ctx := context.Background()
+			for _, step := range steps {
+				if err := announceRoutes(db, batch, step.announce); err != nil {
+					t.Fatalf("%s: announce: %v", step.name, err)
+				}
+				if err := withdrawRoutes(db, batch, step.withdraw); err != nil {
+					t.Fatalf("%s: withdraw: %v", step.name, err)
+				}
+
+				stats, err := db.GetStatsContext(ctx)
+				if err != nil {
+					t.Fatalf("%s: GetStatsContext: %v", step.name, err)
+				}
+				queryV4, queryV6, err := db.GetPrefixDistributionContext(ctx)
+				if err != nil {
+					t.Fatalf("%s: GetPrefixDistributionContext: %v", step.name, err)
+				}
+
+				assertDistribution(t, step.name+": IPv4 distribution", stats.IPv4PrefixDistribution, step.wantV4)
+				assertDistribution(t, step.name+": IPv6 distribution", stats.IPv6PrefixDistribution, step.wantV6)
+				assertDistribution(t, step.name+": IPv4 distribution query", queryV4, step.wantV4)
+				assertDistribution(t, step.name+": IPv6 distribution query", queryV6, step.wantV6)
+			}
+		})
+	}
+}
+
+// announceRoutes writes routes in one UpsertLiveRouteBatch, or with one
+// UpsertLiveRoute each.
+func announceRoutes(db *Database, batch bool, routes []*LiveRoute) error {
+	if batch {
+		return db.UpsertLiveRouteBatch(routes)
+	}
+	for _, route := range routes {
+		if err := db.UpsertLiveRoute(route); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// withdrawRoutes removes routes in one DeleteLiveRouteBatch, or with one
+// DeleteLiveRoute each.
+func withdrawRoutes(db *Database, batch bool, routes []*LiveRoute) error {
+	if !batch {
+		for _, route := range routes {
+			if err := db.DeleteLiveRoute(route.Prefix, route.PeerIP); err != nil {
+				return err
+			}
+		}
+
+		return nil
+	}
+
+	deletions := make([]LiveRouteDeletion, 0, len(routes))
+	for _, route := range routes {
+		deletions = append(deletions, LiveRouteDeletion{
+			Prefix: route.Prefix, PeerIP: route.PeerIP, IPVersion: route.IPVersion,
+		})
+	}
+
+	return db.DeleteLiveRouteBatch(deletions)
+}
+
+// TestDeleteLiveRoutesOfPeer gives two peers IPv4 and IPv6 live routes, some
+// for the same prefixes, and deletes all of one peer's routes. The other peer's
+// routes stay, and the route counts and prefix distribution held in memory
+// equal what is read from the route tables.
+func TestDeleteLiveRoutesOfPeer(t *testing.T) {
+	const (
+		peerIP      = "192.0.2.1"
+		otherPeerIP = "192.0.2.2"
+		sharedV4    = "198.51.100.0/24"
+		sharedV6    = "2001:db8::/32"
+	)
+
+	db, err := New(&config.Config{StateDir: t.TempDir()}, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	ofPeer := func(peer string, route *LiveRoute) *LiveRoute {
+		route.PeerIP = peer
+
+		return route
+	}
+	onlyV6 := mkV6Route("2001:db8:1::/48", 64503, ts)
+	onlyV6.MaskLength = 48
+	if err := db.UpsertLiveRouteBatch([]*LiveRoute{
+		ofPeer(peerIP, mkV4Route(t, sharedV4, 64500, ts)),
+		ofPeer(otherPeerIP, mkV4Route(t, sharedV4, 64500, ts)),
+		ofPeer(peerIP, mkV4Route(t, "203.0.113.0/24", 64501, ts)),
+		ofPeer(peerIP, mkV6Route(sharedV6, 64502, ts)),
+		ofPeer(otherPeerIP, mkV6Route(sharedV6, 64502, ts)),
+		ofPeer(peerIP, onlyV6),
+	}); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+
+	// peerIP has two IPv4 and two IPv6 routes; a second delete finds none.
+	for _, want := range []int{4, 0} {
+		deleted, err := db.DeleteLiveRoutesOfPeer(peerIP)
+		if err != nil {
+			t.Fatalf("DeleteLiveRoutesOfPeer: %v", err)
+		}
+		if deleted != want {
+			t.Errorf("DeleteLiveRoutesOfPeer deleted %d routes, want %d", deleted, want)
+		}
+	}
+
+	ctx := context.Background()
+	for _, prefix := range []string{sharedV4, sharedV6} {
+		routes, _, err := db.GetPrefixDetailsContext(ctx, prefix)
+		if err != nil {
+			t.Fatalf("GetPrefixDetailsContext(%s): %v", prefix, err)
+		}
+		if len(routes) != 1 || routes[0].PeerIP != otherPeerIP {
+			t.Errorf("live routes for %s = %+v, want only the one from %s", prefix, routes, otherPeerIP)
+		}
+	}
+
+	stats, err := db.GetStatsContext(ctx)
+	if err != nil {
+		t.Fatalf("GetStatsContext: %v", err)
+	}
+	tableV4, tableV6, err := db.GetLiveRouteCountsContext(ctx)
+	if err != nil {
+		t.Fatalf("GetLiveRouteCountsContext: %v", err)
+	}
+	if stats.IPv4Routes != 1 || tableV4 != 1 || stats.IPv6Routes != 1 || tableV6 != 1 {
+		t.Errorf("live routes (IPv4, IPv6): (%d, %d) in memory, (%d, %d) in the tables, want (1, 1)",
+			stats.IPv4Routes, stats.IPv6Routes, tableV4, tableV6)
+	}
+	queryV4, queryV6, err := db.GetPrefixDistributionContext(ctx)
+	if err != nil {
+		t.Fatalf("GetPrefixDistributionContext: %v", err)
+	}
+	wantV4 := []PrefixDistribution{{MaskLength: 24, Count: 1}}
+	wantV6 := []PrefixDistribution{{MaskLength: 32, Count: 1}}
+	assertDistribution(t, "IPv4 distribution", stats.IPv4PrefixDistribution, wantV4)
+	assertDistribution(t, "IPv6 distribution", stats.IPv6PrefixDistribution, wantV6)
+	assertDistribution(t, "IPv4 distribution query", queryV4, wantV4)
+	assertDistribution(t, "IPv6 distribution query", queryV6, wantV6)
+}
+
+// TestStatsRouteTimestamps checks the oldest/newest route timestamps are read
+// from the right rows across both tables and parse into time.Time. The old
+// MIN/MAX union query read its result into *time.Time, which the driver could
+// not parse, so it logged a warning every call and left both timestamps nil.
+func TestStatsRouteTimestamps(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ctx := context.Background()
+
+	empty, err := db.GetStatsContext(ctx)
+	if err != nil {
+		t.Fatalf("GetStatsContext on empty database: %v", err)
+	}
+	if empty.OldestRoute != nil || empty.NewestRoute != nil {
+		t.Fatalf("empty database timestamps = (%v, %v), want (nil, nil)",
+			empty.OldestRoute, empty.NewestRoute)
+	}
+
+	base := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	oldest := base
+	newest := base.Add(2 * time.Minute)
+	if err := db.UpsertLiveRouteBatch([]*LiveRoute{
+		mkV4Route(t, "198.51.100.0/24", 64500, base.Add(time.Minute)),
+		mkV4Route(t, "203.0.113.0/24", 64501, oldest),
+		mkV6Route("2001:db8::/32", 64502, newest),
+	}); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+
+	stats, err := db.GetStatsContext(ctx)
+	if err != nil {
+		t.Fatalf("GetStatsContext: %v", err)
+	}
+	if stats.OldestRoute == nil || !stats.OldestRoute.Equal(oldest) {
+		t.Errorf("OldestRoute = %v, want %v", stats.OldestRoute, oldest)
+	}
+	if stats.NewestRoute == nil || !stats.NewestRoute.Equal(newest) {
+		t.Errorf("NewestRoute = %v, want %v", stats.NewestRoute, newest)
+	}
+}
+
+// TestLiveCountsConcurrentReadWrite runs writers and stats readers at once so
+// the race detector proves the counters are safe under concurrent use.
+func TestLiveCountsConcurrentReadWrite(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+
+	const writers = 4
+	var wg sync.WaitGroup
+
+	wg.Add(writers)
+	for w := range writers {
+		go func(base int) {
+			defer wg.Done()
+			for i := range 25 {
+				asn := 65000 + base*100 + i
+				route := mkV6Route("2001:db8::/32", asn, ts)
+				route.PeerIP = "2001:db8::" + uuid.NewString()
+				if err := db.UpsertLiveRoute(route); err != nil {
+					t.Errorf("UpsertLiveRoute: %v", err)
+
+					return
+				}
+			}
+		}(w)
+	}
+
+	var readerWG sync.WaitGroup
+	readerWG.Add(1)
+	stop := make(chan struct{})
+	go func() {
+		defer readerWG.Done()
+		for {
+			select {
+			case <-stop:
+				return
+			default:
+				if _, err := db.GetStatsContext(context.Background()); err != nil {
+					t.Errorf("GetStatsContext: %v", err)
+
+					return
+				}
+			}
+		}
+	}()
+
+	wg.Wait()
+	close(stop)
+	readerWG.Wait()
+
+	stats, err := db.GetStatsContext(context.Background())
+	if err != nil {
+		t.Fatalf("GetStatsContext: %v", err)
+	}
+	if want := writers * 25; stats.IPv6Routes != want {
+		t.Errorf("IPv6Routes = %d, want %d", stats.IPv6Routes, want)
+	}
+	// Every writer announced the same prefix, so it counts once.
+	assertDistribution(t, "IPv6 distribution", stats.IPv6PrefixDistribution,
+		[]PrefixDistribution{{MaskLength: 32, Count: 1}})
+}
+
+type wantCounts struct {
+	asns       int
+	prefixes   int
+	peerings   int
+	peers      int
+	ipv4Routes int
+	ipv6Routes int
+	liveRoutes int
+}
+
+func assertCounts(t *testing.T, when string, got Stats, want wantCounts) {
+	t.Helper()
+
+	if got.ASNs != want.asns {
+		t.Errorf("%s: ASNs = %d, want %d", when, got.ASNs, want.asns)
+	}
+	if got.Prefixes != want.prefixes {
+		t.Errorf("%s: Prefixes = %d, want %d", when, got.Prefixes, want.prefixes)
+	}
+	if got.Peerings != want.peerings {
+		t.Errorf("%s: Peerings = %d, want %d", when, got.Peerings, want.peerings)
+	}
+	if got.Peers != want.peers {
+		t.Errorf("%s: Peers = %d, want %d", when, got.Peers, want.peers)
+	}
+	if got.IPv4Routes != want.ipv4Routes {
+		t.Errorf("%s: IPv4Routes = %d, want %d", when, got.IPv4Routes, want.ipv4Routes)
+	}
+	if got.IPv6Routes != want.ipv6Routes {
+		t.Errorf("%s: IPv6Routes = %d, want %d", when, got.IPv6Routes, want.ipv6Routes)
+	}
+	if got.LiveRoutes != want.liveRoutes {
+		t.Errorf("%s: LiveRoutes = %d, want %d", when, got.LiveRoutes, want.liveRoutes)
+	}
+}
+
+func assertDistribution(t *testing.T, what string, got, want []PrefixDistribution) {
+	t.Helper()
+
+	if !slices.Equal(got, want) {
+		t.Errorf("%s = %v, want %v", what, got, want)
+	}
+}

internal/database/database_test.go

@@ -1,301 +1,730 @@
 package database
 
 import (
-	"net"
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"net/netip"
+	"slices"
+	"sync"
 	"testing"
+	"time"
+
+	"git.eeqj.de/sneak/routewatch/internal/config"
+	"git.eeqj.de/sneak/routewatch/internal/logger"
+	"github.com/google/uuid"
+	"github.com/mattn/go-sqlite3"
 )
 
-func TestIPToUint32(t *testing.T) {
-	tests := []struct {
-		name     string
-		ip       string
-		expected uint32
-	}{
-		{
-			name:     "Simple IP",
-			ip:       "192.168.1.1",
-			expected: 3232235777, // 192<<24 + 168<<16 + 1<<8 + 1
-		},
-		{
-			name:     "Minimum IP",
-			ip:       "0.0.0.0",
-			expected: 0,
-		},
-		{
-			name:     "Maximum IP",
-			ip:       "255.255.255.255",
-			expected: 4294967295,
-		},
-		{
-			name:     "10.0.0.0",
-			ip:       "10.0.0.0",
-			expected: 167772160,
-		},
-		{
-			name:     "172.16.0.0",
-			ip:       "172.16.0.0",
-			expected: 2886729728,
-		},
-		{
-			name:     "8.8.8.8",
-			ip:       "8.8.8.8",
-			expected: 134744072,
-		},
-		{
-			name:     "1.2.3.4",
-			ip:       "1.2.3.4",
-			expected: 16909060,
-		},
+// tempStoreMemory is the PRAGMA temp_store value meaning "hold temp B-trees in
+// memory"; the DSN change must leave temp_store below this so they spill to disk.
+const tempStoreMemory = 2
+
+// autoVacuumIncremental is the PRAGMA auto_vacuum value meaning "incremental".
+const autoVacuumIncremental = 2
+
+// vacuumTestRoutes is how many routes the vacuum test writes and then deletes,
+// enough to leave many free pages in the file.
+const vacuumTestRoutes = 2000
+
+// heldConnections is how many pooled connections the pragma test holds open at
+// once so each is a distinct SQLite connection that parsed the DSN.
+const heldConnections = 5
+
+// testPeerIP is the peer every route in the IP lookup test is learned from.
+const testPeerIP = "192.0.2.254"
+
+// Parameters for the checkpoint-contention regression test.
+const (
+	// contentionIterations is how many batch writes race the checkpoint loop.
+	contentionIterations = 400
+	// contendedASNCount is the small set of ASNs the batches reuse, so most
+	// batches update existing rows and exercise the read-before-write path.
+	contendedASNCount = 16
+	// asnSecondBand offsets a second ASN per batch so each batch writes more
+	// than one row.
+	asnSecondBand = 100
+)
+
+// Parameters for the prefix-length sample tests.
+const (
+	// sampleLimit is how many prefixes the tests ask the sample for.
+	sampleLimit = 10
+	// sampledPrefixCount is how many prefixes the sampling test stores, more
+	// than sampleLimit so the sample has to choose among them.
+	sampledPrefixCount = 30
+	// secondV4PeerIP and secondV6PeerIP are the second peer each prefix is
+	// learned from, besides the one mkV4Route and mkV6Route set.
+	secondV4PeerIP = "192.0.2.2"
+	secondV6PeerIP = "2001:db8::2"
+	// largeSamplePrefixCount is how many prefixes the test of a mask length
+	// with more than maxPrefixesToShuffle prefixes stores: twice that, so about
+	// half of them come after the first maxPrefixesToShuffle+1 in text order.
+	largeSamplePrefixCount = 2 * maxPrefixesToShuffle
+	// largeSampleLimit is how many prefixes that test asks for. Each random
+	// lookup lands after the first maxPrefixesToShuffle+1 in text order about
+	// half the time, so none of them doing so is about as likely as
+	// largeSampleLimit coin tosses all coming up heads.
+	largeSampleLimit = 30
+	// liveRoutesV4Table and liveRoutesV6Table are the live route tables the
+	// tests pass to the sampling steps.
+	liveRoutesV4Table = "live_routes_v4"
+	liveRoutesV6Table = "live_routes_v6"
+)
+
+// TestGetIPInfoFindsMostSpecificLiveRoute stores nested live prefixes for both
+// families and checks that a lookup returns the most specific one covering the
+// address, ErrNoRoute when none covers it, and the next less specific prefix
+// once the only route of the most specific one is withdrawn.
+func TestGetIPInfoFindsMostSpecificLiveRoute(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	// Nested live prefixes, each originated by its own AS.
+	origins := map[string]int{
+		"10.0.0.0/8":        64500,
+		"10.1.0.0/16":       64501,
+		"10.1.2.0/24":       64502,
+		"2001:db8::/32":     64500,
+		"2001:db8:1::/48":   64501,
+		"2001:db8:1:2::/64": 64502,
+	}
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	routes := make([]*LiveRoute, 0, len(origins))
+	for prefix, asn := range origins {
+		routes = append(routes, &LiveRoute{
+			ID:          uuid.New(),
+			Prefix:      prefix,
+			MaskLength:  netip.MustParsePrefix(prefix).Bits(),
+			IPVersion:   detectIPVersion(prefix),
+			OriginASN:   asn,
+			PeerIP:      testPeerIP,
+			ASPath:      []int{asn},
+			NextHop:     testPeerIP,
+			LastUpdated: ts,
+		})
+	}
+	if err := db.UpsertLiveRouteBatch(routes); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
 	}
 
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			ip := net.ParseIP(tt.ip)
-			if ip == nil {
-				t.Fatalf("Failed to parse IP: %s", tt.ip)
+	// lookup checks that ip resolves to the live prefix want, or to ErrNoRoute
+	// when want is empty.
+	lookup := func(ip, want string) {
+		t.Helper()
+
+		info, err := db.GetIPInfo(ip)
+		if want == "" {
+			if !errors.Is(err, ErrNoRoute) {
+				t.Errorf("GetIPInfo(%s) = %+v, %v; want ErrNoRoute", ip, info, err)
 			}
 
-			result := ipToUint32(ip)
-			if result != tt.expected {
-				t.Errorf("ipToUint32(%s) = %d, want %d", tt.ip, result, tt.expected)
-			}
+			return
+		}
+		if err != nil {
+			t.Errorf("GetIPInfo(%s): %v", ip, err)
 
-			// Test with IPv4-mapped IPv6 address
-			ip6 := net.ParseIP(tt.ip).To16()
-			if ip6 != nil {
-				result6 := ipToUint32(ip6)
-				if result6 != tt.expected {
-					t.Errorf("ipToUint32(%s as IPv6) = %d, want %d", tt.ip, result6, tt.expected)
-				}
-			}
-		})
+			return
+		}
+		if info.Netblock != want || info.MaskLength != netip.MustParsePrefix(want).Bits() ||
+			info.ASN != origins[want] {
+			t.Errorf("GetIPInfo(%s) = %s (mask %d) AS%d, want %s AS%d",
+				ip, info.Netblock, info.MaskLength, info.ASN, want, origins[want])
+		}
+	}
+
+	lookup("10.1.2.3", "10.1.2.0/24")
+	lookup("::ffff:10.1.2.3", "10.1.2.0/24")
+	lookup("10.1.3.4", "10.1.0.0/16")
+	lookup("10.2.0.1", "10.0.0.0/8")
+	lookup("192.0.2.1", "")
+	lookup("2001:db8:1:2::3", "2001:db8:1:2::/64")
+	lookup("2001:db8:1:3::4", "2001:db8:1::/48")
+	lookup("2001:db8:2::1", "2001:db8::/32")
+	lookup("2001:db9::1", "")
+
+	err = db.DeleteLiveRouteBatch([]LiveRouteDeletion{
+		{Prefix: "10.1.2.0/24", PeerIP: testPeerIP, IPVersion: ipVersionV4},
+		{Prefix: "2001:db8:1:2::/64", PeerIP: testPeerIP, IPVersion: ipVersionV6},
+	})
+	if err != nil {
+		t.Fatalf("DeleteLiveRouteBatch: %v", err)
+	}
+
+	lookup("10.1.2.3", "10.1.0.0/16")
+	lookup("2001:db8:1:2::3", "2001:db8:1::/48")
+}
+
+// TestGetIPInfoIgnoresShortRoutes checks that the IP lookup does not report a
+// default route, or a route shorter than /8 for IPv4 or /16 for IPv6, as the
+// route for an address, and that a route of exactly /8 or /16, or longer, still
+// is. The prefixes are written out so that a wrong limit fails the test.
+func TestGetIPInfoIgnoresShortRoutes(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	announce := func(prefix string, asn int) {
+		t.Helper()
+
+		err := db.UpsertLiveRouteBatch([]*LiveRoute{{
+			ID:          uuid.New(),
+			Prefix:      prefix,
+			MaskLength:  netip.MustParsePrefix(prefix).Bits(),
+			IPVersion:   detectIPVersion(prefix),
+			OriginASN:   asn,
+			PeerIP:      testPeerIP,
+			ASPath:      []int{asn},
+			NextHop:     testPeerIP,
+			LastUpdated: ts,
+		}})
+		if err != nil {
+			t.Fatalf("UpsertLiveRouteBatch(%s): %v", prefix, err)
+		}
+	}
+
+	// lookup checks that ip resolves to the live prefix netblock from asn.
+	lookup := func(ip, netblock string, asn int) {
+		t.Helper()
+
+		info, err := db.GetIPInfo(ip)
+		if err != nil {
+			t.Errorf("GetIPInfo(%s): %v", ip, err)
+
+			return
+		}
+		if info.Netblock != netblock || info.ASN != asn {
+			t.Errorf("GetIPInfo(%s) = %s AS%d, want %s AS%d", ip, info.Netblock, info.ASN, netblock, asn)
+		}
+	}
+
+	// Default and very short routes, and routes one bit shorter than each limit.
+	announce("2000::/3", 64500)
+	announce("0.0.0.0/0", 64500)
+	announce("2000::/15", 64500)
+	announce("192.0.0.0/7", 64500)
+
+	for _, ip := range []string{"2001:db8::1", "192.0.2.1"} {
+		if info, err := db.GetIPInfo(ip); !errors.Is(err, ErrNoRoute) {
+			t.Errorf("GetIPInfo(%s) with only short routes = %+v, %v; want ErrNoRoute", ip, info, err)
+		}
+	}
+
+	// Routes of exactly the minimum length are used.
+	announce("2001::/16", 64501)
+	announce("192.0.0.0/8", 64501)
+
+	lookup("2001:db8::1", "2001::/16", 64501)
+	lookup("192.0.2.1", "192.0.0.0/8", 64501)
+
+	announce("2001:db8::/32", 64502)
+
+	lookup("2001:db8::1", "2001:db8::/32", 64502)
+}
+
+// TestLiveRouteTablesHoldOneRoutePerPrefixAndPeer checks that each live route
+// table refuses a second route from a peer for a prefix, even with another
+// origin AS. An upsert updates the peer's route before it would insert one, so
+// only an insert straight into the table shows what the table allows.
+func TestLiveRouteTablesHoldOneRoutePerPrefixAndPeer(t *testing.T) {
+	db, err := New(&config.Config{StateDir: t.TempDir()}, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	const otherOriginASN = 64501
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	for _, tt := range []struct {
+		route     *LiveRoute
+		insertSQL string
+	}{
+		{route: mkV4Route(t, "198.51.100.0/24", 64500, ts), insertSQL: insertLiveRouteV4SQL},
+		{route: mkV6Route("2001:db8::/32", 64500, ts), insertSQL: insertLiveRouteV6SQL},
+	} {
+		if err := db.UpsertLiveRoute(tt.route); err != nil {
+			t.Fatalf("UpsertLiveRoute(%s): %v", tt.route.Prefix, err)
+		}
+
+		_, err := db.db.Exec(tt.insertSQL, uuid.NewString(), tt.route.Prefix, tt.route.MaskLength,
+			otherOriginASN, tt.route.PeerIP, "[]", tt.route.NextHop, ts)
+		var sqliteErr sqlite3.Error
+		if !errors.As(err, &sqliteErr) || sqliteErr.ExtendedCode != sqlite3.ErrConstraintUnique {
+			t.Errorf("second route from peer %s for %s: error %v, want a UNIQUE constraint error",
+				tt.route.PeerIP, tt.route.Prefix, err)
+		}
 	}
 }
 
-func TestCalculateIPv4Range(t *testing.T) {
-	tests := []struct {
-		name      string
-		cidr      string
-		wantStart uint32
-		wantEnd   uint32
-		wantErr   bool
-	}{
-		{
-			name:      "Single IP /32",
-			cidr:      "192.168.1.1/32",
-			wantStart: 3232235777,
-			wantEnd:   3232235777,
-		},
-		{
-			name:      "Class C /24",
-			cidr:      "192.168.1.0/24",
-			wantStart: 3232235776, // 192.168.1.0
-			wantEnd:   3232236031, // 192.168.1.255
-		},
-		{
-			name:      "Class B /16",
-			cidr:      "192.168.0.0/16",
-			wantStart: 3232235520, // 192.168.0.0
-			wantEnd:   3232301055, // 192.168.255.255
-		},
-		{
-			name:      "Class A /8",
-			cidr:      "10.0.0.0/8",
-			wantStart: 167772160, // 10.0.0.0
-			wantEnd:   184549375, // 10.255.255.255
-		},
-		{
-			name:      "Entire IPv4 space /0",
-			cidr:      "0.0.0.0/0",
-			wantStart: 0,
-			wantEnd:   4294967295,
-		},
-		{
-			name:      "Small subnet /30",
-			cidr:      "192.168.1.0/30",
-			wantStart: 3232235776, // 192.168.1.0
-			wantEnd:   3232235779, // 192.168.1.3
-		},
-		{
-			name:      "Medium subnet /20",
-			cidr:      "172.16.0.0/20",
-			wantStart: 2886729728, // 172.16.0.0
-			wantEnd:   2886733823, // 172.16.15.255
-		},
-		{
-			name:      "Private range 172.16/12",
-			cidr:      "172.16.0.0/12",
-			wantStart: 2886729728, // 172.16.0.0
-			wantEnd:   2887778303, // 172.31.255.255
-		},
-		{
-			name:      "Google DNS /29",
-			cidr:      "8.8.8.8/29",
-			wantStart: 134744072, // 8.8.8.8 (network is actually 8.8.8.8 with /29)
-			wantEnd:   134744079, // 8.8.8.15
-		},
-		{
-			name:      "Non-zero host bits",
-			cidr:      "192.168.1.5/24",
-			wantStart: 3232235776, // 192.168.1.0 (network address)
-			wantEnd:   3232236031, // 192.168.1.255
-		},
-		{
-			name:    "Invalid CIDR",
-			cidr:    "192.168.1.1/33",
-			wantErr: true,
-		},
-		{
-			name:    "Invalid IP",
-			cidr:    "256.256.256.256/24",
-			wantErr: true,
-		},
-		{
-			name:    "IPv6 CIDR",
-			cidr:    "2001:db8::/32",
-			wantErr: true,
-		},
-		{
-			name:    "Empty CIDR",
-			cidr:    "",
-			wantErr: true,
-		},
-		{
-			name:    "Missing mask",
-			cidr:    "192.168.1.1",
-			wantErr: true,
-		},
+// TestConnectionPoolPragmas holds several pooled connections open at once and
+// checks each one carries the per-connection settings from the DSN, plus the
+// process-wide hard heap limit, and sees the new file with auto_vacuum
+// incremental.
+func TestConnectionPoolPragmas(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ctx := context.Background()
+
+	// Hold distinct connections open simultaneously so the pool must open a new
+	// one (each parsing the DSN) rather than hand back the same connection.
+	conns := make([]*sql.Conn, 0, heldConnections)
+	defer func() {
+		for _, c := range conns {
+			_ = c.Close()
+		}
+	}()
+
+	for i := 0; i < heldConnections; i++ {
+		c, err := db.db.Conn(ctx)
+		if err != nil {
+			t.Fatalf("failed to open connection %d: %v", i, err)
+		}
+		conns = append(conns, c)
 	}
 
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			start, end, err := CalculateIPv4Range(tt.cidr)
+	for i, c := range conns {
+		var cacheSize int
+		if err := c.QueryRowContext(ctx, "PRAGMA cache_size").Scan(&cacheSize); err != nil {
+			t.Fatalf("conn %d: failed to read cache_size: %v", i, err)
+		}
+		if cacheSize != sqliteCacheSizeKiB {
+			t.Errorf("conn %d: cache_size = %d, want %d", i, cacheSize, sqliteCacheSizeKiB)
+		}
 
-			if tt.wantErr {
-				if err == nil {
-					t.Errorf("CalculateIPv4Range(%s) expected error, got nil", tt.cidr)
-				}
+		var busyTimeout int
+		if err := c.QueryRowContext(ctx, "PRAGMA busy_timeout").Scan(&busyTimeout); err != nil {
+			t.Fatalf("conn %d: failed to read busy_timeout: %v", i, err)
+		}
+		if busyTimeout != sqliteBusyTimeoutMs {
+			t.Errorf("conn %d: busy_timeout = %d, want %d", i, busyTimeout, sqliteBusyTimeoutMs)
+		}
+
+		var tempStore int
+		if err := c.QueryRowContext(ctx, "PRAGMA temp_store").Scan(&tempStore); err != nil {
+			t.Fatalf("conn %d: failed to read temp_store: %v", i, err)
+		}
+		if tempStore == tempStoreMemory {
+			t.Errorf("conn %d: temp_store = %d, want anything but %d (MEMORY)", i, tempStore, tempStoreMemory)
+		}
+
+		var hardHeapLimit int64
+		if err := c.QueryRowContext(ctx, "PRAGMA hard_heap_limit").Scan(&hardHeapLimit); err != nil {
+			t.Fatalf("conn %d: failed to read hard_heap_limit: %v", i, err)
+		}
+		if hardHeapLimit != sqliteHardHeapLimitBytes {
+			t.Errorf("conn %d: hard_heap_limit = %d, want %d", i, hardHeapLimit, sqliteHardHeapLimitBytes)
+		}
+
+		var autoVacuum int
+		if err := c.QueryRowContext(ctx, "PRAGMA auto_vacuum").Scan(&autoVacuum); err != nil {
+			t.Fatalf("conn %d: failed to read auto_vacuum: %v", i, err)
+		}
+		if autoVacuum != autoVacuumIncremental {
+			t.Errorf("conn %d: auto_vacuum = %d, want %d (incremental)", i, autoVacuum, autoVacuumIncremental)
+		}
+	}
+}
+
+// TestVacuumReturnsFreePages checks that after routes are deleted from a new
+// database, one Vacuum call returns every page they used. The deletes leave
+// fewer free pages than the 1000 Vacuum frees per call, so none may remain.
+// With auto_vacuum off (issue https://git.eeqj.de/sneak/routewatch/issues/43)
+// the free pages stayed in the file, and with the PRAGMA run by ExecContext
+// Vacuum freed only one page per call.
+func TestVacuumReturnsFreePages(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ctx := context.Background()
+	ts := time.Now().UTC()
+	const asn = 64500
+
+	routes := make([]*LiveRoute, 0, vacuumTestRoutes)
+	deletions := make([]LiveRouteDeletion, 0, vacuumTestRoutes)
+	for i := range vacuumTestRoutes {
+		route := mkV4Route(t, fmt.Sprintf("10.%d.%d.0/24", i/256, i%256), asn, ts)
+		routes = append(routes, route)
+		deletions = append(deletions, LiveRouteDeletion{
+			Prefix:    route.Prefix,
+			PeerIP:    route.PeerIP,
+			IPVersion: ipVersionV4,
+		})
+	}
+
+	if err := db.UpsertLiveRouteBatch(routes); err != nil {
+		t.Fatalf("failed to write routes: %v", err)
+	}
+	if err := db.DeleteLiveRouteBatch(deletions); err != nil {
+		t.Fatalf("failed to delete routes: %v", err)
+	}
+
+	var before int
+	if err := db.db.QueryRowContext(ctx, "PRAGMA freelist_count").Scan(&before); err != nil {
+		t.Fatalf("failed to read freelist_count: %v", err)
+	}
+	if before == 0 {
+		t.Fatalf("no free pages after deleting %d routes", vacuumTestRoutes)
+	}
+
+	if err := db.Vacuum(ctx); err != nil {
+		t.Fatalf("Vacuum failed: %v", err)
+	}
+
+	var after int
+	if err := db.db.QueryRowContext(ctx, "PRAGMA freelist_count").Scan(&after); err != nil {
+		t.Fatalf("failed to read freelist_count: %v", err)
+	}
+	if after != 0 {
+		t.Errorf("free pages after Vacuum = %d of %d, want 0", after, before)
+	}
+}
+
+// TestBatchWriteDuringCheckpoint reproduces issue #25. A batch write reads
+// (SELECT) before it writes (INSERT/UPDATE). Under the default deferred locking
+// the transaction begins as a reader and, when the maintainer's WAL checkpoint
+// holds the write lock, its upgrade to writer fails immediately with "database
+// is locked" without honouring busy_timeout, dropping the batch. With
+// _txlock=immediate the transaction takes the write lock at BEGIN and waits, so
+// no batch is dropped. The checkpoint runs without the Database mutex, exactly
+// as the background maintainer does in production.
+func TestBatchWriteDuringCheckpoint(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ctx, cancel := context.WithCancel(context.Background())
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		for {
+			select {
+			case <-ctx.Done():
 				return
+			default:
+				_ = db.Checkpoint(ctx) // errors are the checkpoint's own to absorb
 			}
+		}
+	}()
 
-			if err != nil {
-				t.Errorf("CalculateIPv4Range(%s) unexpected error: %v", tt.cidr, err)
-				return
-			}
+	ts := time.Now().UTC()
+	for i := 0; i < contentionIterations; i++ {
+		asns := map[int]time.Time{
+			i % contendedASNCount:                   ts,
+			(i % contendedASNCount) + asnSecondBand: ts,
+		}
+		if err := db.GetOrCreateASNBatch(asns); err != nil {
+			cancel()
+			wg.Wait()
+			t.Fatalf("batch write failed under checkpoint contention: %v", err)
+		}
+	}
 
-			if start != tt.wantStart {
-				t.Errorf("CalculateIPv4Range(%s) start = %d, want %d", tt.cidr, start, tt.wantStart)
-			}
+	cancel()
+	wg.Wait()
+}
 
-			if end != tt.wantEnd {
-				t.Errorf("CalculateIPv4Range(%s) end = %d, want %d", tt.cidr, end, tt.wantEnd)
-			}
+// TestGetRandomPrefixesByLengthListsPrefixOnce stores one prefix of each
+// family learned from two peers in the same second and checks that the
+// prefix-length sample lists each of them once.
+func TestGetRandomPrefixesByLengthListsPrefixOnce(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
 
-			// Verify that start <= end
-			if start > end {
-				t.Errorf("CalculateIPv4Range(%s) start (%d) > end (%d)", tt.cidr, start, end)
-			}
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
 
-			// Verify the range size matches the CIDR mask
-			if !tt.wantErr && tt.cidr != "" {
-				_, ipNet, _ := net.ParseCIDR(tt.cidr)
-				if ipNet != nil {
-					ones, bits := ipNet.Mask.Size()
-					expectedSize := uint32(1) << uint(bits-ones)
-					actualSize := end - start + 1
-					if actualSize != expectedSize {
-						t.Errorf("CalculateIPv4Range(%s) range size = %d, want %d", tt.cidr, actualSize, expectedSize)
-					}
-				}
-			}
-		})
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	v4First := mkV4Route(t, "198.51.100.0/24", 64500, ts)
+	v4Second := mkV4Route(t, "198.51.100.0/24", 64500, ts)
+	v4Second.PeerIP = secondV4PeerIP
+	v6First := mkV6Route("2001:db8::/32", 64500, ts)
+	v6Second := mkV6Route("2001:db8::/32", 64500, ts)
+	v6Second.PeerIP = secondV6PeerIP
+	if err := db.UpsertLiveRouteBatch([]*LiveRoute{v4First, v4Second, v6First, v6Second}); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+
+	for _, want := range []*LiveRoute{v4First, v6First} {
+		routes, err := db.GetRandomPrefixesByLength(want.MaskLength, want.IPVersion, sampleLimit)
+		if err != nil {
+			t.Fatalf("GetRandomPrefixesByLength(%d, %d): %v", want.MaskLength, want.IPVersion, err)
+		}
+		if len(routes) != 1 || routes[0].Prefix != want.Prefix {
+			t.Errorf("GetRandomPrefixesByLength(%d, %d) = %+v, want %s listed once",
+				want.MaskLength, want.IPVersion, routes, want.Prefix)
+		}
 	}
 }
 
-func TestIPv4RangeIntegration(t *testing.T) {
-	// Test that our functions work correctly together
-	tests := []struct {
-		name          string
-		cidr          string
-		testIPs       []string
-		shouldContain []bool
-	}{
-		{
-			name: "192.168.1.0/24",
-			cidr: "192.168.1.0/24",
-			testIPs: []string{
-				"192.168.1.0",
-				"192.168.1.1",
-				"192.168.1.255",
-				"192.168.0.255",
-				"192.168.2.0",
-			},
-			shouldContain: []bool{true, true, true, false, false},
-		},
-		{
-			name: "10.0.0.0/8",
-			cidr: "10.0.0.0/8",
-			testIPs: []string{
-				"10.0.0.0",
-				"10.255.255.255",
-				"10.1.2.3",
-				"9.255.255.255",
-				"11.0.0.0",
-			},
-			shouldContain: []bool{true, true, true, false, false},
-		},
-		{
-			name: "172.16.0.0/12",
-			cidr: "172.16.0.0/12",
-			testIPs: []string{
-				"172.16.0.0",
-				"172.31.255.255",
-				"172.20.1.1",
-				"172.15.255.255",
-				"172.32.0.0",
-			},
-			shouldContain: []bool{true, true, true, false, false},
-		},
+// TestGetRandomPrefixesByLengthListsNewestRoute stores a prefix learned from
+// two peers at different times, the older route first, and checks that the
+// prefix-length sample lists the newer route.
+func TestGetRandomPrefixesByLengthListsNewestRoute(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	older := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	olderRoute := mkV4Route(t, "198.51.100.0/24", 64500, older)
+	newerRoute := mkV4Route(t, "198.51.100.0/24", 64500, older.Add(time.Minute))
+	newerRoute.PeerIP = secondV4PeerIP
+	if err := db.UpsertLiveRouteBatch([]*LiveRoute{olderRoute, newerRoute}); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
 	}
 
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			start, end, err := CalculateIPv4Range(tt.cidr)
-			if err != nil {
-				t.Fatalf("Failed to calculate range for %s: %v", tt.cidr, err)
-			}
-
-			for i, testIP := range tt.testIPs {
-				ip := net.ParseIP(testIP)
-				if ip == nil {
-					t.Fatalf("Failed to parse test IP: %s", testIP)
-				}
-
-				ipUint := ipToUint32(ip)
-				contained := ipUint >= start && ipUint <= end
-
-				if contained != tt.shouldContain[i] {
-					t.Errorf("IP %s in range %s: got %v, want %v", testIP, tt.cidr, contained, tt.shouldContain[i])
-				}
-			}
-		})
+	routes, err := db.GetRandomPrefixesByLength(newerRoute.MaskLength, ipVersionV4, sampleLimit)
+	if err != nil {
+		t.Fatalf("GetRandomPrefixesByLength: %v", err)
+	}
+	if len(routes) != 1 || routes[0].PeerIP != newerRoute.PeerIP {
+		t.Errorf("GetRandomPrefixesByLength = %+v, want only the newer route, from %s",
+			routes, newerRoute.PeerIP)
 	}
 }
 
-func BenchmarkIPToUint32(b *testing.B) {
-	ip := net.ParseIP("192.168.1.1")
-	b.ResetTimer()
+// TestGetRandomPrefixesByLengthSamplesManyPrefixes stores more /24 prefixes
+// than the sample asks for, each followed by a /16 so that routes of another
+// mask length sit between the /24 rows, and each prefix learned from two peers
+// in the same second. It checks both the sample the pages get, picked from the
+// shuffled prefixes, and the random lookups used for a mask length with more
+// than maxPrefixesToShuffle prefixes.
+func TestGetRandomPrefixesByLengthSamplesManyPrefixes(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
 
-	for i := 0; i < b.N; i++ {
-		_ = ipToUint32(ip)
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	var routes []*LiveRoute
+	var stored []string
+	for i := range sampledPrefixCount {
+		prefix := fmt.Sprintf("10.0.%d.0/24", i)
+		for _, p := range []string{prefix, fmt.Sprintf("172.%d.0.0/16", i)} {
+			first := mkV4Route(t, p, 64500, ts)
+			second := mkV4Route(t, p, 64500, ts)
+			second.PeerIP = secondV4PeerIP
+			routes = append(routes, first, second)
+		}
+		stored = append(stored, prefix)
+	}
+	if err := db.UpsertLiveRouteBatch(routes); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+	slices.Sort(stored)
+
+	maskLength := routes[0].MaskLength
+	sample, err := db.GetRandomPrefixesByLength(maskLength, ipVersionV4, sampleLimit)
+	if err != nil {
+		t.Fatalf("GetRandomPrefixesByLength: %v", err)
+	}
+	var listed []string
+	for _, route := range sample {
+		listed = append(listed, route.Prefix)
+	}
+	checkPrefixSample(t, "GetRandomPrefixesByLength", listed, stored)
+
+	looked, err := db.samplePrefixesByLength(
+		context.Background(), liveRoutesV4Table, maskLength, sampleLimit, nil)
+	if err != nil {
+		t.Fatalf("samplePrefixesByLength: %v", err)
+	}
+	checkPrefixSample(t, "samplePrefixesByLength", looked, stored)
+}
+
+// checkPrefixSample checks that sample lists sampleLimit prefixes, each once
+// and each one of stored, and that it is not just the first sampleLimit of
+// stored, which is in text order.
+func checkPrefixSample(t *testing.T, name string, sample, stored []string) {
+	t.Helper()
+
+	if len(sample) != sampleLimit {
+		t.Errorf("%s listed %d prefixes, want %d", name, len(sample), sampleLimit)
+	}
+	listed := make(map[string]bool)
+	for _, prefix := range sample {
+		if listed[prefix] || !slices.Contains(stored, prefix) {
+			t.Errorf("%s lists %s twice or it is not one of the /24s", name, prefix)
+		}
+		listed[prefix] = true
+	}
+	if slices.Equal(slices.Sorted(slices.Values(sample)), stored[:sampleLimit]) {
+		t.Errorf("%s lists just the first %d prefixes in text order", name, sampleLimit)
 	}
 }
 
-func BenchmarkCalculateIPv4Range(b *testing.B) {
-	cidr := "192.168.0.0/16"
-	b.ResetTimer()
+// TestGetRandomPrefixesByLengthSamplesPastFirstPrefixes stores more prefixes
+// of one mask length than maxPrefixesToShuffle. It checks that
+// firstPrefixesByLength reads just the first maxPrefixesToShuffle+1 in text
+// order, and that the sample lists the prefixes asked for, each once, some of
+// them after those first ones, which only the random lookups reach.
+func TestGetRandomPrefixesByLengthSamplesPastFirstPrefixes(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
 
-	for i := 0; i < b.N; i++ {
-		_, _, _ = CalculateIPv4Range(cidr)
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	var routes []*LiveRoute
+	var stored []string
+	for i := range largeSamplePrefixCount {
+		route := mkV6Route(fmt.Sprintf("2001:%x::/32", i), 64500, ts)
+		routes = append(routes, route)
+		stored = append(stored, route.Prefix)
+	}
+	if err := db.UpsertLiveRouteBatch(routes); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+	slices.Sort(stored)
+	firstPrefixes := stored[:maxPrefixesToShuffle+1]
+
+	maskLength := routes[0].MaskLength
+	read, err := db.firstPrefixesByLength(
+		context.Background(), liveRoutesV6Table, maskLength, maxPrefixesToShuffle+1)
+	if err != nil {
+		t.Fatalf("firstPrefixesByLength: %v", err)
+	}
+	if !slices.Equal(read, firstPrefixes) {
+		t.Errorf("firstPrefixesByLength read %d prefixes, want the first %d in text order",
+			len(read), len(firstPrefixes))
+	}
+
+	sample, err := db.GetRandomPrefixesByLength(maskLength, ipVersionV6, largeSampleLimit)
+	if err != nil {
+		t.Fatalf("GetRandomPrefixesByLength: %v", err)
+	}
+	if len(sample) != largeSampleLimit {
+		t.Errorf("GetRandomPrefixesByLength listed %d prefixes, want %d", len(sample), largeSampleLimit)
+	}
+	listed := make(map[string]bool)
+	pastFirstPrefixes := 0
+	for _, route := range sample {
+		if listed[route.Prefix] {
+			t.Errorf("GetRandomPrefixesByLength lists %s twice", route.Prefix)
+		}
+		listed[route.Prefix] = true
+		if !slices.Contains(firstPrefixes, route.Prefix) {
+			pastFirstPrefixes++
+		}
+	}
+	if pastFirstPrefixes == 0 {
+		t.Errorf("GetRandomPrefixesByLength lists only prefixes among the first %d in text order",
+			len(firstPrefixes))
+	}
+}
+
+// TestSamplePrefixesByLengthFillsUpFromShuffled stores a single prefix, so
+// every random lookup lands on it, and checks that the sample still lists
+// sampleLimit prefixes: the stored one, then the shuffled ones in order. The
+// stored prefix is the second shuffled one, so the fill-up must skip it.
+func TestSamplePrefixesByLengthFillsUpFromShuffled(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	var shuffled []string
+	for i := range sampledPrefixCount {
+		shuffled = append(shuffled, fmt.Sprintf("10.0.%d.0/24", i))
+	}
+	route := mkV4Route(t, shuffled[1], 64500, time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC))
+	if err := db.UpsertLiveRouteBatch([]*LiveRoute{route}); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+
+	sample, err := db.samplePrefixesByLength(
+		context.Background(), liveRoutesV4Table, route.MaskLength, sampleLimit, shuffled)
+	if err != nil {
+		t.Fatalf("samplePrefixesByLength: %v", err)
+	}
+	want := append([]string{shuffled[1], shuffled[0]}, shuffled[2:sampleLimit]...)
+	if !slices.Equal(sample, want) {
+		t.Errorf("samplePrefixesByLength = %v, want %v", sample, want)
+	}
+}
+
+// TestGetRandomPrefixesByLengthSkipsWithdrawnRoutes withdraws a route after
+// storing it, as can happen between the steps of GetRandomPrefixesByLength. It
+// checks that the random lookups pick nothing for a mask length with no route
+// left, and that only the prefixes that still have a route get their newest
+// route listed.
+func TestGetRandomPrefixesByLengthSkipsWithdrawnRoutes(t *testing.T) {
+	cfg := &config.Config{StateDir: t.TempDir()}
+
+	db, err := New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	kept := mkV4Route(t, "198.51.100.0/24", 64500, ts)
+	withdrawn := mkV4Route(t, "172.16.0.0/16", 64500, ts)
+	if err := db.UpsertLiveRouteBatch([]*LiveRoute{kept, withdrawn}); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+	if err := db.DeleteLiveRoute(withdrawn.Prefix, withdrawn.PeerIP); err != nil {
+		t.Fatalf("DeleteLiveRoute: %v", err)
+	}
+
+	ctx := context.Background()
+	sample, err := db.samplePrefixesByLength(
+		ctx, liveRoutesV4Table, withdrawn.MaskLength, sampleLimit, []string{withdrawn.Prefix})
+	if err != nil {
+		t.Fatalf("samplePrefixesByLength: %v", err)
+	}
+	if len(sample) != 0 {
+		t.Errorf("samplePrefixesByLength = %v, want none for a mask length with no route left", sample)
+	}
+
+	routes, err := db.newestRouteOfEachPrefix(
+		ctx, liveRoutesV4Table, ipVersionV4, []string{withdrawn.Prefix, kept.Prefix})
+	if err != nil {
+		t.Fatalf("newestRouteOfEachPrefix: %v", err)
+	}
+	if len(routes) != 1 || routes[0].Prefix != kept.Prefix {
+		t.Errorf("newestRouteOfEachPrefix = %+v, want only the route of %s", routes, kept.Prefix)
 	}
 }

internal/database/interface.go

@@ -18,6 +18,8 @@ type Stats struct {
 	Peers                  int
 	FileSizeBytes          int64
 	LiveRoutes             int
+	IPv4Routes             int
+	IPv6Routes             int
 	OldestRoute            *time.Time
 	NewestRoute            *time.Time
 	IPv4PrefixDistribution []PrefixDistribution
@@ -53,16 +55,15 @@ type Store interface {
 	// Live route operations
 	UpsertLiveRoute(route *LiveRoute) error
 	UpsertLiveRouteBatch(routes []*LiveRoute) error
-	DeleteLiveRoute(prefix string, originASN int, peerIP string) error
+	DeleteLiveRoute(prefix, peerIP string) error
 	DeleteLiveRouteBatch(deletions []LiveRouteDeletion) error
+	DeleteLiveRoutesOfPeer(peerIP string) (deleted int, err error)
 	GetPrefixDistribution() (ipv4 []PrefixDistribution, ipv6 []PrefixDistribution, err error)
 	GetPrefixDistributionContext(ctx context.Context) (ipv4 []PrefixDistribution, ipv6 []PrefixDistribution, err error)
 	GetLiveRouteCounts() (ipv4Count, ipv6Count int, err error)
 	GetLiveRouteCountsContext(ctx context.Context) (ipv4Count, ipv6Count int, err error)
 
 	// IP lookup operations
-	GetASInfoForIP(ip string) (*ASInfo, error)
-	GetASInfoForIPContext(ctx context.Context, ip string) (*ASInfo, error)
 	GetIPInfo(ip string) (*IPInfo, error)
 	GetIPInfoContext(ctx context.Context, ip string) (*IPInfo, error)
 
@@ -76,8 +77,8 @@ type Store interface {
 	GetASDetailsContext(ctx context.Context, asn int) (*ASN, []LiveRoute, error)
 	GetASPeers(asn int) ([]ASPeer, error)
 	GetASPeersContext(ctx context.Context, asn int) ([]ASPeer, error)
-	GetPrefixDetails(prefix string) ([]LiveRoute, error)
-	GetPrefixDetailsContext(ctx context.Context, prefix string) ([]LiveRoute, error)
+	GetPrefixDetails(prefix string) ([]LiveRoute, map[int]ASN, error)
+	GetPrefixDetailsContext(ctx context.Context, prefix string) ([]LiveRoute, map[int]ASN, error)
 	GetRandomPrefixesByLength(maskLength, ipVersion, limit int) ([]LiveRoute, error)
 	GetRandomPrefixesByLengthContext(ctx context.Context, maskLength, ipVersion, limit int) ([]LiveRoute, error)
 

internal/database/models.go

@@ -77,9 +77,6 @@ type LiveRoute struct {
 	ASPath      []int     `json:"as_path"`
 	NextHop     string    `json:"next_hop"`
 	LastUpdated time.Time `json:"last_updated"`
-	// IPv4 range fields for fast lookups (nil for IPv6)
-	V4IPStart *uint32 `json:"v4_ip_start,omitempty"`
-	V4IPEnd   *uint32 `json:"v4_ip_end,omitempty"`
 }
 
 // PrefixDistribution represents the distribution of prefixes by mask length
@@ -88,16 +85,6 @@ type PrefixDistribution struct {
 	Count      int `json:"count"`
 }
 
-// ASInfo represents AS information for an IP lookup (legacy format)
-type ASInfo struct {
-	ASN         int       `json:"asn"`
-	Handle      string    `json:"handle"`
-	Description string    `json:"description"`
-	Prefix      string    `json:"prefix"`
-	LastUpdated time.Time `json:"last_updated"`
-	Age         string    `json:"age"`
-}
-
 // IPInfo represents comprehensive IP information for the /ip endpoint
 type IPInfo struct {
 	IP         string   `json:"ip"`
@@ -127,7 +114,6 @@ type IPInfo struct {
 // LiveRouteDeletion represents parameters for deleting a live route
 type LiveRouteDeletion struct {
 	Prefix    string
-	OriginASN int
 	PeerIP    string
 	IPVersion int
 }

internal/database/schema.sql

@@ -107,10 +107,10 @@ CREATE TABLE IF NOT EXISTS live_routes_v4 (
 	as_path TEXT NOT NULL, -- JSON array
 	next_hop TEXT NOT NULL,
 	last_updated DATETIME NOT NULL,
-	-- IPv4 range columns for fast lookups
-	ip_start INTEGER NOT NULL, -- Start of IPv4 range as 32-bit unsigned int
-	ip_end INTEGER NOT NULL,    -- End of IPv4 range as 32-bit unsigned int
-	UNIQUE(prefix, origin_asn, peer_ip)
+	-- A peer has at most one route for a prefix. peer_ip comes first so that
+	-- this key also finds all of a peer's routes, when its BGP session goes
+	-- down; lookups by prefix use the prefix index below.
+	UNIQUE(peer_ip, prefix)
 );
 
 -- IPv6 routing table maintained by PrefixHandler
@@ -123,22 +123,22 @@ CREATE TABLE IF NOT EXISTS live_routes_v6 (
 	as_path TEXT NOT NULL, -- JSON array
 	next_hop TEXT NOT NULL,
 	last_updated DATETIME NOT NULL,
-	-- Note: IPv6 doesn't use integer range columns
-	UNIQUE(prefix, origin_asn, peer_ip)
+	-- As in live_routes_v4: peer_ip first, to find all of a peer's routes.
+	UNIQUE(peer_ip, prefix)
 );
 
 -- Indexes for live_routes_v4 table
-CREATE INDEX IF NOT EXISTS idx_live_routes_v4_prefix ON live_routes_v4(prefix);
+-- Finds a prefix's newest route in one search, whatever the number of peers.
+CREATE INDEX IF NOT EXISTS idx_live_routes_v4_prefix_last_updated ON live_routes_v4(prefix, last_updated);
 CREATE INDEX IF NOT EXISTS idx_live_routes_v4_mask_length ON live_routes_v4(mask_length);
 CREATE INDEX IF NOT EXISTS idx_live_routes_v4_origin_asn ON live_routes_v4(origin_asn);
 CREATE INDEX IF NOT EXISTS idx_live_routes_v4_last_updated ON live_routes_v4(last_updated);
--- Indexes for IPv4 range queries
-CREATE INDEX IF NOT EXISTS idx_live_routes_v4_ip_range ON live_routes_v4(ip_start, ip_end);
 -- Index to optimize prefix distribution queries
 CREATE INDEX IF NOT EXISTS idx_live_routes_v4_mask_prefix ON live_routes_v4(mask_length, prefix);
 
 -- Indexes for live_routes_v6 table
-CREATE INDEX IF NOT EXISTS idx_live_routes_v6_prefix ON live_routes_v6(prefix);
+-- Finds a prefix's newest route in one search, whatever the number of peers.
+CREATE INDEX IF NOT EXISTS idx_live_routes_v6_prefix_last_updated ON live_routes_v6(prefix, last_updated);
 CREATE INDEX IF NOT EXISTS idx_live_routes_v6_mask_length ON live_routes_v6(mask_length);
 CREATE INDEX IF NOT EXISTS idx_live_routes_v6_origin_asn ON live_routes_v6(origin_asn);
 CREATE INDEX IF NOT EXISTS idx_live_routes_v6_last_updated ON live_routes_v6(last_updated);

internal/database/utils.go

@@ -1,6 +1,8 @@
 package database
 
 import (
+	"fmt"
+	"net"
 	"strings"
 
 	"github.com/google/uuid"
@@ -18,3 +20,14 @@ func detectIPVersion(prefix string) int {
 
 	return ipVersionV4
 }
+
+// prefixMaskLength returns the mask length of a prefix such as 192.0.2.0/24.
+func prefixMaskLength(prefix string) (int, error) {
+	_, network, err := net.ParseCIDR(prefix)
+	if err != nil {
+		return 0, fmt.Errorf("invalid prefix %s: %w", prefix, err)
+	}
+	maskLength, _ := network.Mask.Size()
+
+	return maskLength, nil
+}

internal/metrics/metrics.go

@@ -60,17 +60,22 @@ func New() *Tracker {
 	}
 }
 
-// SetConnected updates the connection status
+// SetConnected updates the connection status. Every connection after the
+// first counts one reconnect.
 func (t *Tracker) SetConnected(connected bool) {
-	wasConnected := t.isConnected.Swap(connected)
-	if connected {
-		t.mu.Lock()
-		t.connectedSince = time.Now()
-		t.mu.Unlock()
-		// Increment reconnect count (but not for the initial connection)
-		if wasConnected || t.reconnectCount.Load() > 0 {
-			t.reconnectCount.Add(1)
-		}
+	t.isConnected.Store(connected)
+	if !connected {
+		return
+	}
+
+	t.mu.Lock()
+	// connectedSince is zero until the first connection.
+	connectedBefore := !t.connectedSince.IsZero()
+	t.connectedSince = time.Now()
+	t.mu.Unlock()
+
+	if connectedBefore {
+		t.reconnectCount.Add(1)
 	}
 }
 

internal/metrics/metrics_test.go

@@ -0,0 +1,21 @@
+package metrics
+
+import "testing"
+
+// TestReconnectCount connects three times with a disconnect between each, the
+// way the streamer does, and expects every connection after the first to count
+// one reconnect.
+func TestReconnectCount(t *testing.T) {
+	tracker := New()
+
+	tracker.SetConnected(true)
+	tracker.SetConnected(false)
+	tracker.SetConnected(true)
+	tracker.SetConnected(false)
+	tracker.SetConnected(true)
+
+	const wantReconnects = 2
+	if got := tracker.GetReconnectCount(); got != wantReconnects {
+		t.Fatalf("reconnect count = %d, want %d", got, wantReconnects)
+	}
+}

internal/ristypes/ris.go

@@ -6,6 +6,22 @@ import (
 	"time"
 )
 
+// Message types and the session state the handlers act on, as the feed writes
+// them in a message's type and state fields.
+const (
+	// MessageTypeUpdate is a BGP UPDATE: announcements and withdrawals.
+	MessageTypeUpdate = "UPDATE"
+
+	// MessageTypeState is a change in the state of the BGP session between
+	// the collector and the peer.
+	MessageTypeState = "STATE"
+
+	// StateDown is the state of a STATE message whose session has ended: the
+	// collector no longer has any of the peer's routes, and sends no
+	// withdrawals for them.
+	StateDown = "down"
+)
+
 // ASPath represents a BGP AS path as a slice of AS numbers.
 // It handles JSON unmarshaling of both simple arrays and nested AS sets,
 // flattening any nested structures into a single sequence of AS numbers.
@@ -63,24 +79,30 @@ type RISLiveMessage struct {
 // the actual BGP update data including AS path, communities, announcements,
 // and withdrawals.
 type RISMessage struct {
-	Type            string            `json:"type"`
-	Timestamp       float64           `json:"timestamp"`
-	ParsedTimestamp time.Time         `json:"-"` // Parsed from Timestamp field
-	Peer            string            `json:"peer"`
-	PeerASN         string            `json:"peer_asn"`
-	ID              string            `json:"id"`
-	Host            string            `json:"host"`
-	RRC             string            `json:"rrc,omitempty"`
-	MrtTime         float64           `json:"mrt_time,omitempty"`
-	SocketTime      float64           `json:"socket_time,omitempty"`
-	Path            ASPath            `json:"path,omitempty"`
-	Community       [][]int           `json:"community,omitempty"`
-	Origin          string            `json:"origin,omitempty"`
-	MED             *int              `json:"med,omitempty"`
-	LocalPref       *int              `json:"local_pref,omitempty"`
-	Announcements   []RISAnnouncement `json:"announcements,omitempty"`
-	Withdrawals     []string          `json:"withdrawals,omitempty"`
-	Raw             string            `json:"raw,omitempty"`
+	Type            string    `json:"type"`
+	Timestamp       float64   `json:"timestamp"`
+	ParsedTimestamp time.Time `json:"-"` // Parsed from Timestamp field
+	Peer            string    `json:"peer"`
+	PeerASN         string    `json:"peer_asn"`
+	ID              string    `json:"id"`
+	Host            string    `json:"host"`
+	RRC             string    `json:"rrc,omitempty"`
+	MrtTime         float64   `json:"mrt_time,omitempty"`
+	SocketTime      float64   `json:"socket_time,omitempty"`
+	Path            ASPath    `json:"path,omitempty"`
+	// Community and Raw are present in the feed but read by no handler.
+	// They are the largest fields on a message that lives in up to four
+	// handler queues, so json:"-" keeps them out of the decoded message
+	// to save queue memory. Do not decode them without a consumer.
+	Community     [][]int           `json:"-"`
+	Origin        string            `json:"origin,omitempty"`
+	MED           *int              `json:"med,omitempty"`
+	LocalPref     *int              `json:"local_pref,omitempty"`
+	Announcements []RISAnnouncement `json:"announcements,omitempty"`
+	Withdrawals   []string          `json:"withdrawals,omitempty"`
+	Raw           string            `json:"-"`
+	// State is set on STATE messages: the session's new state, such as StateDown.
+	State string `json:"state,omitempty"`
 }
 
 // RISAnnouncement represents a BGP route announcement within a RIS message.

internal/ristypes/ris_test.go

@@ -0,0 +1,67 @@
+package ristypes
+
+import (
+	"bufio"
+	"encoding/json"
+	"os"
+	"testing"
+)
+
+// messageExamplesPath is the captured RIS Live feed used as decode fixtures,
+// one JSON message per line.
+const messageExamplesPath = "../../docs/message-examples.json"
+
+// TestDecodeDropsCommunityAndRaw decodes every captured message the way the
+// streamer does and checks that the fields no handler reads (Community, Raw)
+// stay empty while the fields handlers use (Path, Announcements) still decode.
+func TestDecodeDropsCommunityAndRaw(t *testing.T) {
+	f, err := os.Open(messageExamplesPath)
+	if err != nil {
+		t.Fatalf("open fixtures: %v", err)
+	}
+	defer f.Close()
+
+	var messages, withPath, withAnnouncements int
+
+	scanner := bufio.NewScanner(f)
+	scanner.Buffer(make([]byte, 0, 64*1024), 1024*1024)
+	for scanner.Scan() {
+		line := scanner.Bytes()
+		if len(line) == 0 {
+			continue
+		}
+
+		var wrapper RISLiveMessage
+		if err := json.Unmarshal(line, &wrapper); err != nil {
+			t.Fatalf("unmarshal message %d: %v", messages+1, err)
+		}
+		messages++
+
+		msg := wrapper.Data
+		if msg.Community != nil {
+			t.Errorf("message %d: Community decoded, want empty: %v", messages, msg.Community)
+		}
+		if msg.Raw != "" {
+			t.Errorf("message %d: Raw decoded, want empty", messages)
+		}
+
+		if len(msg.Path) > 0 {
+			withPath++
+		}
+		if len(msg.Announcements) > 0 {
+			withAnnouncements++
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		t.Fatalf("scan fixtures: %v", err)
+	}
+
+	if messages == 0 {
+		t.Fatal("no messages decoded from fixtures")
+	}
+	// The fixtures include announcement messages; a used field must still decode,
+	// otherwise an empty Community/Raw would prove nothing.
+	if withPath == 0 || withAnnouncements == 0 {
+		t.Fatalf("used fields did not decode: withPath=%d withAnnouncements=%d", withPath, withAnnouncements)
+	}
+}

internal/routewatch/app_integration_test.go

@@ -205,7 +205,7 @@ func (m *mockStore) UpsertLiveRoute(route *database.LiveRoute) error {
 }
 
 // DeleteLiveRoute mock implementation
-func (m *mockStore) DeleteLiveRoute(prefix string, originASN int, peerIP string) error {
+func (m *mockStore) DeleteLiveRoute(prefix, peerIP string) error {
 	// Simple mock - just return nil
 	return nil
 }
@@ -232,25 +232,6 @@ func (m *mockStore) GetLiveRouteCountsContext(ctx context.Context) (ipv4Count, i
 	return m.GetLiveRouteCounts()
 }
 
-// GetASInfoForIP mock implementation
-func (m *mockStore) GetASInfoForIP(ip string) (*database.ASInfo, error) {
-	// Simple mock - return a test AS
-	now := time.Now()
-	return &database.ASInfo{
-		ASN:         15169,
-		Handle:      "GOOGLE",
-		Description: "Google LLC",
-		Prefix:      "8.8.8.0/24",
-		LastUpdated: now.Add(-5 * time.Minute),
-		Age:         "5m0s",
-	}, nil
-}
-
-// GetASInfoForIPContext mock implementation with context support
-func (m *mockStore) GetASInfoForIPContext(ctx context.Context, ip string) (*database.ASInfo, error) {
-	return m.GetASInfoForIP(ip)
-}
-
 // GetASDetails mock implementation
 func (m *mockStore) GetASDetails(asn int) (*database.ASN, []database.LiveRoute, error) {
 	m.mu.Lock()
@@ -271,13 +252,15 @@ func (m *mockStore) GetASDetailsContext(ctx context.Context, asn int) (*database
 }
 
 // GetPrefixDetails mock implementation
-func (m *mockStore) GetPrefixDetails(prefix string) ([]database.LiveRoute, error) {
+func (m *mockStore) GetPrefixDetails(prefix string) ([]database.LiveRoute, map[int]database.ASN, error) {
 	// Return empty routes for now
-	return []database.LiveRoute{}, nil
+	return []database.LiveRoute{}, map[int]database.ASN{}, nil
 }
 
 // GetPrefixDetailsContext mock implementation with context support
-func (m *mockStore) GetPrefixDetailsContext(ctx context.Context, prefix string) ([]database.LiveRoute, error) {
+func (m *mockStore) GetPrefixDetailsContext(
+	ctx context.Context, prefix string,
+) ([]database.LiveRoute, map[int]database.ASN, error) {
 	return m.GetPrefixDetails(prefix)
 }
 
@@ -381,6 +364,12 @@ func (m *mockStore) DeleteLiveRouteBatch(deletions []database.LiveRouteDeletion)
 	return nil
 }
 
+// DeleteLiveRoutesOfPeer mock implementation
+func (m *mockStore) DeleteLiveRoutesOfPeer(peerIP string) (int, error) {
+	// Simple mock - deletes nothing
+	return 0, nil
+}
+
 // GetOrCreateASNBatch mock implementation
 func (m *mockStore) GetOrCreateASNBatch(asns map[int]time.Time) error {
 	m.mu.Lock()
@@ -426,6 +415,9 @@ func (m *mockStore) Ping(ctx context.Context) error {
 }
 
 func TestRouteWatchLiveFeed(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping live RIPE RIS network feed test in short mode; run without -short to include it")
+	}
 
 	// Create mock database
 	mockDB := newMockStore()
@@ -447,7 +439,7 @@ func TestRouteWatchLiveFeed(t *testing.T) {
 	}
 
 	// Create server
-	srv := server.New(mockDB, s, logger)
+	srv := server.New(mockDB, s, logger, cfg)
 
 	// Create RouteWatch with 5 second limit
 	deps := Dependencies{

internal/routewatch/ashandler.go

@@ -10,13 +10,21 @@ import (
 )
 
 const (
-	// asHandlerQueueSize is the queue capacity for ASN operations
-	// DO NOT set this higher than 100000 without explicit instructions
-	asHandlerQueueSize = 100000
+	// asHandlerQueueSize is the queue capacity for ASN operations, about 4
+	// seconds of feed at peak. The streamer drops rather than blocks when a
+	// queue is full, so this bounds memory. Batches still flush on a timer
+	// (asnBatchTimeout), so a queue smaller than asnBatchSize is fine.
+	asHandlerQueueSize = 20000
 
 	// asnBatchSize is the number of ASN operations to batch together
 	asnBatchSize = 30000
 
+	// asnBatchMaxSize is the most ASN operations the batch holds while the
+	// flush goroutine writes the previous one: ten batches, about 10 MiB
+	// (README "Memory"). At this size HandleMessage waits until the flush
+	// goroutine takes the batch.
+	asnBatchMaxSize = 300000
+
 	// asnBatchTimeout is the maximum time to wait before flushing a batch
 	// DO NOT reduce this timeout - larger batches are more efficient
 	asnBatchTimeout = 2 * time.Second
@@ -30,12 +38,16 @@ type ASHandler struct {
 	db     database.Store
 	logger *logger.Logger
 
-	// Batching
-	mu        sync.Mutex
-	batch     []asnOp
-	lastFlush time.Time
-	stopCh    chan struct{}
-	wg        sync.WaitGroup
+	// Batching. mu guards batch only: the flush goroutine takes the batch
+	// under mu and writes it after releasing mu, so HandleMessage waits for
+	// a database write only while batch is at asnBatchMaxSize.
+	mu          sync.Mutex
+	batch       []asnOp
+	batchTaken  sync.Cond     // signalled when the flush goroutine takes batch; its L is &mu
+	batchFullCh chan struct{} // wakes the flush goroutine when batch is full
+	lastFlush   time.Time     // used only by the flush goroutine
+	stopCh      chan struct{}
+	wg          sync.WaitGroup
 }
 
 type asnOp struct {
@@ -50,12 +62,14 @@ type asnOp struct {
 // background goroutine is terminated.
 func NewASHandler(db database.Store, logger *logger.Logger) *ASHandler {
 	h := &ASHandler{
-		db:        db,
-		logger:    logger,
-		batch:     make([]asnOp, 0, asnBatchSize),
-		lastFlush: time.Now(),
-		stopCh:    make(chan struct{}),
+		db:          db,
+		logger:      logger,
+		batch:       make([]asnOp, 0, asnBatchSize),
+		batchFullCh: make(chan struct{}, 1),
+		lastFlush:   time.Now(),
+		stopCh:      make(chan struct{}),
 	}
+	h.batchTaken.L = &h.mu
 
 	// Start the flush timer goroutine
 	h.wg.Add(1)
@@ -83,8 +97,8 @@ func (h *ASHandler) QueueCapacity() int {
 // HandleMessage processes a RIS Live BGP message by extracting all ASNs from
 // the AS path and queuing them for batch insertion into the database. The
 // origin ASN (last element in the path) and all transit ASNs are recorded
-// with their associated timestamps. The batch is automatically flushed when
-// it reaches the configured size threshold.
+// with their associated timestamps. When the batch reaches the configured size
+// threshold, the flush goroutine is woken to write it.
 func (h *ASHandler) HandleMessage(msg *ristypes.RISMessage) {
 	// Use the pre-parsed timestamp
 	timestamp := msg.ParsedTimestamp
@@ -98,6 +112,13 @@ func (h *ASHandler) HandleMessage(msg *ristypes.RISMessage) {
 	h.mu.Lock()
 	defer h.mu.Unlock()
 
+	// While the batch is at its maximum size, wait until the flush goroutine
+	// takes it. Meanwhile the handler takes nothing off its queue, which
+	// fills, and the streamer drops messages for it.
+	for len(h.batch) >= asnBatchMaxSize {
+		h.batchTaken.Wait()
+	}
+
 	// Queue origin ASN operation
 	if originASN > 0 {
 		h.batch = append(h.batch, asnOp{
@@ -116,13 +137,19 @@ func (h *ASHandler) HandleMessage(msg *ristypes.RISMessage) {
 		}
 	}
 
-	// Check if we need to flush
+	// A full batch wakes the flush goroutine. If it is writing, the wake-up
+	// waits in batchFullCh and the batch keeps growing until the write ends
+	// or the batch reaches asnBatchMaxSize.
 	if len(h.batch) >= asnBatchSize {
-		h.flushBatchLocked()
+		select {
+		case h.batchFullCh <- struct{}{}:
+		default: // already woken
+		}
 	}
 }
 
-// flushLoop runs in a goroutine and periodically flushes batches
+// flushLoop runs in a goroutine, the only one that writes the batch: it
+// flushes when the batch is full, periodically, and once more on Stop.
 func (h *ASHandler) flushLoop() {
 	defer h.wg.Done()
 	ticker := time.NewTicker(asnBatchTimeout)
@@ -131,31 +158,47 @@ func (h *ASHandler) flushLoop() {
 	for {
 		select {
 		case <-ticker.C:
-			h.mu.Lock()
 			if time.Since(h.lastFlush) >= asnBatchTimeout {
-				h.flushBatchLocked()
+				h.flushBatch()
 			}
-			h.mu.Unlock()
+		case <-h.batchFullCh:
+			h.flushBatch()
 		case <-h.stopCh:
 			// Final flush
-			h.mu.Lock()
-			h.flushBatchLocked()
-			h.mu.Unlock()
+			h.flushBatch()
 
 			return
 		}
 	}
 }
 
-// flushBatchLocked flushes the ASN batch to the database (must be called with mutex held)
-func (h *ASHandler) flushBatchLocked() {
+// takeBatch returns the pending operations and leaves an empty batch in their
+// place for HandleMessage to fill.
+func (h *ASHandler) takeBatch() []asnOp {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
 	if len(h.batch) == 0 {
+		return nil
+	}
+	batch := h.batch
+	h.batch = make([]asnOp, 0, asnBatchSize)
+	h.batchTaken.Broadcast()
+
+	return batch
+}
+
+// flushBatch takes the pending batch and writes it to the database, without
+// holding the mutex during the write.
+func (h *ASHandler) flushBatch() {
+	batch := h.takeBatch()
+	if len(batch) == 0 {
 		return
 	}
 
 	// Process ASNs first (deduped)
 	asnMap := make(map[int]time.Time)
-	for _, op := range h.batch {
+	for _, op := range batch {
 		if existing, ok := asnMap[op.number]; !ok || op.timestamp.After(existing) {
 			asnMap[op.number] = op.timestamp
 		}
@@ -166,8 +209,6 @@ func (h *ASHandler) flushBatchLocked() {
 		h.logger.Error("Failed to process ASN batch", "error", err, "count", len(asnMap))
 	}
 
-	// Clear batch
-	h.batch = h.batch[:0]
 	h.lastFlush = time.Now()
 }
 

internal/routewatch/batchwrite_test.go

@@ -0,0 +1,374 @@
+package routewatch
+
+import (
+	"slices"
+	"sync"
+	"testing"
+	"time"
+
+	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/logger"
+	"git.eeqj.de/sneak/routewatch/internal/ristypes"
+)
+
+const (
+	// handleMessageTimeout is how long a test waits for HandleMessage to
+	// return, or for a write to start, before it fails.
+	handleMessageTimeout = 2 * time.Second
+
+	// stillWaitingAfter is how long a test watches a HandleMessage that must
+	// wait. One that does not wait returns well within it.
+	stillWaitingAfter = 100 * time.Millisecond
+)
+
+// blockingStore is a mockStore whose batch writes for the AS, peer and prefix
+// handlers wait until the test calls releaseWrites. writeStarted is closed when
+// the first of them starts. It records what each write was given.
+type blockingStore struct {
+	*mockStore
+
+	release      chan struct{}
+	releaseOnce  sync.Once
+	writeStarted chan struct{}
+	startOnce    sync.Once
+
+	mu       sync.Mutex
+	prefixes map[string]bool
+	asns     map[int]bool
+	peers    map[string]bool
+}
+
+func newBlockingStore() *blockingStore {
+	return &blockingStore{
+		mockStore:    newMockStore(),
+		release:      make(chan struct{}),
+		writeStarted: make(chan struct{}),
+		prefixes:     make(map[string]bool),
+		asns:         make(map[int]bool),
+		peers:        make(map[string]bool),
+	}
+}
+
+func (s *blockingStore) waitForRelease() {
+	s.startOnce.Do(func() { close(s.writeStarted) })
+	<-s.release
+}
+
+// releaseWrites lets the held writes, and all later ones, finish. A second call
+// does nothing.
+func (s *blockingStore) releaseWrites() {
+	s.releaseOnce.Do(func() { close(s.release) })
+}
+
+func (s *blockingStore) UpsertLiveRouteBatch(routes []*database.LiveRoute) error {
+	s.waitForRelease()
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for _, route := range routes {
+		s.prefixes[route.Prefix] = true
+	}
+
+	return nil
+}
+
+func (s *blockingStore) GetOrCreateASNBatch(asns map[int]time.Time) error {
+	s.waitForRelease()
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for asn := range asns {
+		s.asns[asn] = true
+	}
+
+	return nil
+}
+
+func (s *blockingStore) UpdatePeerBatch(peers map[string]database.PeerUpdate) error {
+	s.waitForRelease()
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for peerIP := range peers {
+		s.peers[peerIP] = true
+	}
+
+	return nil
+}
+
+// returnsInTime reports whether f returns within handleMessageTimeout.
+func returnsInTime(f func()) bool {
+	done := make(chan struct{})
+	go func() {
+		f()
+		close(done)
+	}()
+
+	select {
+	case <-done:
+		return true
+	case <-time.After(handleMessageTimeout):
+		return false
+	}
+}
+
+// startBlockedWrite hands h the messages in fill, which fill its batch so that
+// the handler writes it to store, and waits until that write starts. store
+// holds it until the test calls releaseWrites.
+func startBlockedWrite(
+	t *testing.T,
+	store *blockingStore,
+	h interface{ HandleMessage(*ristypes.RISMessage) },
+	fill []*ristypes.RISMessage,
+) {
+	t.Helper()
+
+	if !returnsInTime(func() {
+		for _, msg := range fill {
+			h.HandleMessage(msg)
+		}
+	}) {
+		t.Fatal("HandleMessage did not return after filling the batch: it waits for the database write")
+	}
+
+	select {
+	case <-store.writeStarted:
+	case <-time.After(handleMessageTimeout):
+		t.Fatal("the handler did not write its full batch")
+	}
+}
+
+// handleWhileAWriteIsBlocked starts a blocked write with the messages in fill
+// and hands h the message extra while store holds the write. HandleMessage must
+// return each time. Then it lets the writes finish and stops h, which writes
+// what it holds.
+func handleWhileAWriteIsBlocked(
+	t *testing.T,
+	store *blockingStore,
+	h interface {
+		HandleMessage(*ristypes.RISMessage)
+		Stop()
+	},
+	fill []*ristypes.RISMessage,
+	extra *ristypes.RISMessage,
+) {
+	t.Helper()
+	defer h.Stop()
+	defer store.releaseWrites()
+
+	startBlockedWrite(t, store, h, fill)
+
+	if !returnsInTime(func() { h.HandleMessage(extra) }) {
+		t.Fatal("HandleMessage did not return while a database write was blocked")
+	}
+}
+
+// handleAtMaxBatchSize starts a blocked write with the messages in fill, then,
+// while store holds the write, hands h the messages in toMax, which bring its
+// next batch to its maximum size, and the message extra. HandleMessage for
+// extra must wait until the test lets the write finish, and return after. Then
+// it stops h, which writes what it holds.
+func handleAtMaxBatchSize(
+	t *testing.T,
+	store *blockingStore,
+	h interface {
+		HandleMessage(*ristypes.RISMessage)
+		Stop()
+	},
+	fill, toMax []*ristypes.RISMessage,
+	extra *ristypes.RISMessage,
+) {
+	t.Helper()
+	defer h.Stop()
+	defer store.releaseWrites()
+
+	startBlockedWrite(t, store, h, fill)
+	for _, msg := range toMax {
+		h.HandleMessage(msg)
+	}
+
+	returned := make(chan struct{})
+	go func() {
+		h.HandleMessage(extra)
+		close(returned)
+	}()
+
+	select {
+	case <-returned:
+		t.Fatal("HandleMessage returned while the batch was at its maximum size and a write was blocked")
+	case <-time.After(stillWaitingAfter):
+	}
+
+	store.releaseWrites()
+	select {
+	case <-returned:
+	case <-time.After(handleMessageTimeout):
+		t.Fatal("HandleMessage did not return after the database write finished")
+	}
+}
+
+// prefixAnnouncement returns a message in which testPeerIP announces prefixes
+// with origin AS testASNA.
+func prefixAnnouncement(prefixes []string) *ristypes.RISMessage {
+	return &ristypes.RISMessage{
+		Peer:          testPeerIP,
+		Path:          ristypes.ASPath{testASNA},
+		Announcements: []ristypes.RISAnnouncement{{NextHop: testPeerIP, Prefixes: prefixes}},
+	}
+}
+
+func TestPrefixHandlerHandlesMessagesWhileAWriteIsBlocked(t *testing.T) {
+	const (
+		fillPrefix  = "192.0.2.0/24"
+		extraPrefix = "198.51.100.0/24"
+	)
+
+	store := newBlockingStore()
+	h := NewPrefixHandler(store, logger.New())
+	handleWhileAWriteIsBlocked(t, store, h,
+		[]*ristypes.RISMessage{prefixAnnouncement(slices.Repeat([]string{fillPrefix}, prefixBatchSize))},
+		prefixAnnouncement([]string{extraPrefix}))
+
+	store.mu.Lock()
+	defer store.mu.Unlock()
+	if !store.prefixes[extraPrefix] {
+		t.Errorf("Stop did not write %s, handled while a write was blocked", extraPrefix)
+	}
+}
+
+func TestASHandlerHandlesMessagesWhileAWriteIsBlocked(t *testing.T) {
+	store := newBlockingStore()
+	h := NewASHandler(store, logger.New())
+	handleWhileAWriteIsBlocked(t, store, h,
+		[]*ristypes.RISMessage{{Path: slices.Repeat(ristypes.ASPath{testASNA}, asnBatchSize)}},
+		&ristypes.RISMessage{Path: ristypes.ASPath{testASNB}})
+
+	store.mu.Lock()
+	defer store.mu.Unlock()
+	if !store.asns[testASNB] {
+		t.Errorf("Stop did not write AS%d, handled while a write was blocked", testASNB)
+	}
+}
+
+func TestPeerHandlerHandlesMessagesWhileAWriteIsBlocked(t *testing.T) {
+	const otherPeerIP = "2001:db8:ffff::2"
+
+	store := newBlockingStore()
+	h := NewPeerHandler(store, logger.New())
+	handleWhileAWriteIsBlocked(t, store, h,
+		slices.Repeat([]*ristypes.RISMessage{{Peer: testPeerIP}}, peerBatchSize),
+		&ristypes.RISMessage{Peer: otherPeerIP})
+
+	store.mu.Lock()
+	defer store.mu.Unlock()
+	if !store.peers[otherPeerIP] {
+		t.Errorf("Stop did not write peer %s, handled while a write was blocked", otherPeerIP)
+	}
+}
+
+func TestPrefixHandlerWaitsAtTheMaximumBatchSize(t *testing.T) {
+	const (
+		fillPrefix  = "192.0.2.0/24"
+		extraPrefix = "198.51.100.0/24"
+	)
+
+	store := newBlockingStore()
+	h := NewPrefixHandler(store, logger.New())
+	handleAtMaxBatchSize(t, store, h,
+		[]*ristypes.RISMessage{prefixAnnouncement(slices.Repeat([]string{fillPrefix}, prefixBatchSize))},
+		[]*ristypes.RISMessage{prefixAnnouncement(slices.Repeat([]string{fillPrefix}, prefixBatchMaxSize))},
+		prefixAnnouncement([]string{extraPrefix}))
+
+	store.mu.Lock()
+	defer store.mu.Unlock()
+	if !store.prefixes[extraPrefix] {
+		t.Errorf("Stop did not write %s, handled after the batch reached its maximum size", extraPrefix)
+	}
+}
+
+func TestASHandlerWaitsAtTheMaximumBatchSize(t *testing.T) {
+	store := newBlockingStore()
+	h := NewASHandler(store, logger.New())
+	handleAtMaxBatchSize(t, store, h,
+		[]*ristypes.RISMessage{{Path: slices.Repeat(ristypes.ASPath{testASNA}, asnBatchSize)}},
+		[]*ristypes.RISMessage{{Path: slices.Repeat(ristypes.ASPath{testASNA}, asnBatchMaxSize)}},
+		&ristypes.RISMessage{Path: ristypes.ASPath{testASNB}})
+
+	store.mu.Lock()
+	defer store.mu.Unlock()
+	if !store.asns[testASNB] {
+		t.Errorf("Stop did not write AS%d, handled after the batch reached its maximum size", testASNB)
+	}
+}
+
+func TestPeerHandlerWaitsAtTheMaximumBatchSize(t *testing.T) {
+	const otherPeerIP = "2001:db8:ffff::2"
+
+	store := newBlockingStore()
+	h := NewPeerHandler(store, logger.New())
+	handleAtMaxBatchSize(t, store, h,
+		slices.Repeat([]*ristypes.RISMessage{{Peer: testPeerIP}}, peerBatchSize),
+		slices.Repeat([]*ristypes.RISMessage{{Peer: testPeerIP}}, peerBatchMaxSize),
+		&ristypes.RISMessage{Peer: otherPeerIP})
+
+	store.mu.Lock()
+	defer store.mu.Unlock()
+	if !store.peers[otherPeerIP] {
+		t.Errorf("Stop did not write peer %s, handled after the batch reached its maximum size", otherPeerIP)
+	}
+}
+
+// TestHandlersWakeTheFlushGoroutineWhenTheBatchIsFull hands each handler, built
+// without its flush goroutine so that nothing takes a wake-up, one update short
+// of a full batch, and a second one exactly a full batch. Only the full batch
+// leaves a wake-up in batchFullCh.
+func TestHandlersWakeTheFlushGoroutineWhenTheBatchIsFull(t *testing.T) {
+	tests := []struct {
+		name      string
+		batchSize int
+		// handle hands a new handler n updates and returns its batchFullCh.
+		handle func(n int) chan struct{}
+	}{
+		{
+			name:      "prefix",
+			batchSize: prefixBatchSize,
+			handle: func(n int) chan struct{} {
+				h := &PrefixHandler{batchFullCh: make(chan struct{}, 1)}
+				h.HandleMessage(prefixAnnouncement(slices.Repeat([]string{"192.0.2.0/24"}, n)))
+
+				return h.batchFullCh
+			},
+		},
+		{
+			name:      "AS",
+			batchSize: asnBatchSize,
+			handle: func(n int) chan struct{} {
+				h := &ASHandler{batchFullCh: make(chan struct{}, 1)}
+				// The origin AS and each AS in the path are one update each.
+				h.HandleMessage(&ristypes.RISMessage{Path: slices.Repeat(ristypes.ASPath{testASNA}, n-1)})
+
+				return h.batchFullCh
+			},
+		},
+		{
+			name:      "peer",
+			batchSize: peerBatchSize,
+			handle: func(n int) chan struct{} {
+				h := &PeerHandler{batchFullCh: make(chan struct{}, 1)}
+				for range n {
+					h.HandleMessage(&ristypes.RISMessage{Peer: testPeerIP})
+				}
+
+				return h.batchFullCh
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := len(tt.handle(tt.batchSize - 1)); got != 0 {
+				t.Errorf("one update short of a full batch left %d wake-ups, want none", got)
+			}
+			if got := len(tt.handle(tt.batchSize)); got != 1 {
+				t.Errorf("a full batch left %d wake-ups, want 1", got)
+			}
+		})
+	}
+}

internal/routewatch/cli.go

@@ -20,6 +20,8 @@ const (
 	debugInterval = 60 * time.Second
 	// bytesPerMB is bytes per megabyte
 	bytesPerMB = 1024 * 1024
+	// failureExitCode is the exit status when RouteWatch stops on an error
+	failureExitCode = 1
 )
 
 // logDebugStats logs goroutine count and memory usage
@@ -83,6 +85,9 @@ func CLIEntry() {
 					go func() {
 						if err := rw.Run(ctx); err != nil {
 							logger.Error("RouteWatch error", "error", err)
+							if err := shutdowner.Shutdown(fx.ExitCode(failureExitCode)); err != nil {
+								logger.Error("Failed to shutdown gracefully", "error", err)
+							}
 						}
 					}()
 

internal/routewatch/peerhandler.go

@@ -14,12 +14,21 @@ import (
 )
 
 const (
-	// peerHandlerQueueSize is the queue capacity for peer tracking operations
-	peerHandlerQueueSize = 100000
+	// peerHandlerQueueSize is the queue capacity for peer tracking operations,
+	// about 4 seconds of feed at peak. The streamer drops messages rather than
+	// blocks when a queue is full (a STATE message waits for room), so this
+	// bounds memory. Batches still flush on a timer (peerBatchTimeout).
+	peerHandlerQueueSize = 20000
 
 	// peerBatchSize is the number of peer updates to batch together
 	peerBatchSize = 10000
 
+	// peerBatchMaxSize is the most peer updates the batch holds while the
+	// flush goroutine writes the previous one: ten batches, about 10 MiB
+	// (README "Memory"). At this size HandleMessage waits until the flush
+	// goroutine takes the batch.
+	peerBatchMaxSize = 100000
+
 	// peerBatchTimeout is the maximum time to wait before flushing a batch
 	peerBatchTimeout = 2 * time.Second
 )
@@ -32,12 +41,16 @@ type PeerHandler struct {
 	db     database.Store
 	logger *logger.Logger
 
-	// Batching
-	mu        sync.Mutex
-	peerBatch []peerUpdate
-	lastFlush time.Time
-	stopCh    chan struct{}
-	wg        sync.WaitGroup
+	// Batching. mu guards peerBatch only: the flush goroutine takes the batch
+	// under mu and writes it after releasing mu, so HandleMessage waits for
+	// a database write only while peerBatch is at peerBatchMaxSize.
+	mu          sync.Mutex
+	peerBatch   []peerUpdate
+	batchTaken  sync.Cond     // signalled when the flush goroutine takes peerBatch; its L is &mu
+	batchFullCh chan struct{} // wakes the flush goroutine when peerBatch is full
+	lastFlush   time.Time     // used only by the flush goroutine
+	stopCh      chan struct{}
+	wg          sync.WaitGroup
 }
 
 type peerUpdate struct {
@@ -53,12 +66,14 @@ type peerUpdate struct {
 // should be stopped by calling Stop when it is no longer needed.
 func NewPeerHandler(db database.Store, logger *logger.Logger) *PeerHandler {
 	h := &PeerHandler{
-		db:        db,
-		logger:    logger,
-		peerBatch: make([]peerUpdate, 0, peerBatchSize),
-		lastFlush: time.Now(),
-		stopCh:    make(chan struct{}),
+		db:          db,
+		logger:      logger,
+		peerBatch:   make([]peerUpdate, 0, peerBatchSize),
+		batchFullCh: make(chan struct{}, 1),
+		lastFlush:   time.Now(),
+		stopCh:      make(chan struct{}),
 	}
+	h.batchTaken.L = &h.mu
 
 	// Start the flush timer goroutine
 	h.wg.Add(1)
@@ -84,8 +99,8 @@ func (h *PeerHandler) QueueCapacity() int {
 
 // HandleMessage processes a RIS message to track peer information.
 // It extracts the peer IP address and ASN from the message and adds
-// the update to an internal batch. When the batch reaches peerBatchSize
-// or the batch timeout expires, the batch is flushed to the database.
+// the update to an internal batch. The flush goroutine writes the batch to the
+// database when it reaches peerBatchSize or the batch timeout expires.
 func (h *PeerHandler) HandleMessage(msg *ristypes.RISMessage) {
 	// Parse peer ASN from string
 	peerASN := 0
@@ -98,6 +113,13 @@ func (h *PeerHandler) HandleMessage(msg *ristypes.RISMessage) {
 	h.mu.Lock()
 	defer h.mu.Unlock()
 
+	// While the batch is at its maximum size, wait until the flush goroutine
+	// takes it. Meanwhile the handler takes nothing off its queue, which
+	// fills, and the streamer drops messages for it.
+	for len(h.peerBatch) >= peerBatchMaxSize {
+		h.batchTaken.Wait()
+	}
+
 	// Add to batch
 	h.peerBatch = append(h.peerBatch, peerUpdate{
 		peerIP:      msg.Peer,
@@ -106,13 +128,19 @@ func (h *PeerHandler) HandleMessage(msg *ristypes.RISMessage) {
 		timestamp:   msg.ParsedTimestamp,
 	})
 
-	// Check if we need to flush
+	// A full batch wakes the flush goroutine. If it is writing, the wake-up
+	// waits in batchFullCh and the batch keeps growing until the write ends
+	// or the batch reaches peerBatchMaxSize.
 	if len(h.peerBatch) >= peerBatchSize {
-		h.flushBatchLocked()
+		select {
+		case h.batchFullCh <- struct{}{}:
+		default: // already woken
+		}
 	}
 }
 
-// flushLoop runs in a goroutine and periodically flushes batches
+// flushLoop runs in a goroutine, the only one that writes the batch: it
+// flushes when the batch is full, periodically, and once more on Stop.
 func (h *PeerHandler) flushLoop() {
 	defer h.wg.Done()
 	ticker := time.NewTicker(peerBatchTimeout)
@@ -121,31 +149,47 @@ func (h *PeerHandler) flushLoop() {
 	for {
 		select {
 		case <-ticker.C:
-			h.mu.Lock()
 			if time.Since(h.lastFlush) >= peerBatchTimeout {
-				h.flushBatchLocked()
+				h.flushBatch()
 			}
-			h.mu.Unlock()
+		case <-h.batchFullCh:
+			h.flushBatch()
 		case <-h.stopCh:
 			// Final flush
-			h.mu.Lock()
-			h.flushBatchLocked()
-			h.mu.Unlock()
+			h.flushBatch()
 
 			return
 		}
 	}
 }
 
-// flushBatchLocked flushes the peer batch to the database (must be called with mutex held)
-func (h *PeerHandler) flushBatchLocked() {
+// takeBatch returns the pending updates and leaves an empty batch in their
+// place for HandleMessage to fill.
+func (h *PeerHandler) takeBatch() []peerUpdate {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
 	if len(h.peerBatch) == 0 {
+		return nil
+	}
+	batch := h.peerBatch
+	h.peerBatch = make([]peerUpdate, 0, peerBatchSize)
+	h.batchTaken.Broadcast()
+
+	return batch
+}
+
+// flushBatch takes the pending batch and writes it to the database, without
+// holding the mutex during the write.
+func (h *PeerHandler) flushBatch() {
+	batch := h.takeBatch()
+	if len(batch) == 0 {
 		return
 	}
 
 	// Deduplicate by peer IP, keeping the latest update for each peer
 	peerMap := make(map[string]peerUpdate)
-	for _, update := range h.peerBatch {
+	for _, update := range batch {
 		if existing, ok := peerMap[update.peerIP]; !ok || update.timestamp.After(existing.timestamp) {
 			peerMap[update.peerIP] = update
 		}
@@ -167,8 +211,6 @@ func (h *PeerHandler) flushBatchLocked() {
 		h.logger.Error("Failed to process peer batch", "error", err, "count", len(dbPeerMap))
 	}
 
-	// Clear batch
-	h.peerBatch = h.peerBatch[:0]
 	h.lastFlush = time.Now()
 }
 

internal/routewatch/peeringhandler.go

@@ -11,29 +11,25 @@ import (
 )
 
 const (
-	// peeringHandlerQueueSize defines the buffer capacity for the peering
-	// handler's message queue. This should be large enough to handle bursts
-	// of BGP UPDATE messages without blocking.
-	peeringHandlerQueueSize = 100000
+	// peeringHandlerQueueSize is the buffer capacity for the peering handler's
+	// message queue, about 4 seconds of feed at peak. The streamer drops
+	// rather than blocks when a queue is full, so this bounds memory.
+	peeringHandlerQueueSize = 20000
 
 	// minPathLengthForPeering specifies the minimum number of ASNs required
 	// in a BGP AS path to extract peering relationships. A path with fewer
 	// than 2 ASNs cannot contain any peering information.
 	minPathLengthForPeering = 2
 
-	// pathExpirationTime determines how long AS paths are kept in memory
-	// before being eligible for pruning. Paths older than this are removed
-	// to prevent unbounded memory growth.
-	pathExpirationTime = 30 * time.Minute
-
 	// peeringProcessInterval controls how frequently the handler processes
 	// accumulated AS paths and extracts peering relationships to store
 	// in the database.
 	peeringProcessInterval = 30 * time.Second
 
-	// pathPruneInterval determines how often the handler checks for and
-	// removes expired AS paths from memory.
-	pathPruneInterval = 5 * time.Minute
+	// maxTrackedPaths bounds how many distinct AS paths are held in memory
+	// between processing runs. Once the map is full, further new paths are
+	// dropped and counted until the next run empties it.
+	maxTrackedPaths = 500000
 )
 
 // PeeringHandler processes BGP UPDATE messages to extract and track
@@ -46,17 +42,17 @@ type PeeringHandler struct {
 	logger *logger.Logger
 
 	// In-memory AS path tracking
-	mu      sync.RWMutex
-	asPaths map[string]time.Time // key is JSON-encoded AS path
+	mu           sync.Mutex
+	asPaths      map[string]time.Time // key is JSON-encoded AS path
+	droppedPaths int                  // paths dropped because the map was full
 
 	stopCh chan struct{}
 }
 
 // NewPeeringHandler creates and initializes a new PeeringHandler with the
-// provided database store and logger. It starts two background goroutines:
-// one for periodic processing of accumulated AS paths into peering records,
-// and one for pruning expired paths from memory. The handler begins
-// processing immediately upon creation.
+// provided database store and logger. It starts one background goroutine that
+// periodically processes accumulated AS paths into peering records. The
+// handler begins processing immediately upon creation.
 func NewPeeringHandler(db database.Store, logger *logger.Logger) *PeeringHandler {
 	h := &PeeringHandler{
 		db:      db,
@@ -65,9 +61,8 @@ func NewPeeringHandler(db database.Store, logger *logger.Logger) *PeeringHandler
 		stopCh:  make(chan struct{}),
 	}
 
-	// Start the periodic processing goroutines
+	// Start the periodic processing goroutine
 	go h.processLoop()
-	go h.pruneLoop()
 
 	return h
 }
@@ -106,9 +101,18 @@ func (h *PeeringHandler) HandleMessage(msg *ristypes.RISMessage) {
 
 		return
 	}
+	key := string(pathJSON)
 
 	h.mu.Lock()
-	h.asPaths[string(pathJSON)] = timestamp
+	if _, exists := h.asPaths[key]; exists {
+		// Already tracked: refresh its timestamp.
+		h.asPaths[key] = timestamp
+	} else if len(h.asPaths) >= maxTrackedPaths {
+		// Map is full; drop this new path and count it.
+		h.droppedPaths++
+	} else {
+		h.asPaths[key] = timestamp
+	}
 	h.mu.Unlock()
 }
 
@@ -130,41 +134,6 @@ func (h *PeeringHandler) processLoop() {
 	}
 }
 
-// pruneLoop runs periodically to remove old AS paths
-func (h *PeeringHandler) pruneLoop() {
-	ticker := time.NewTicker(pathPruneInterval)
-	defer ticker.Stop()
-
-	for {
-		select {
-		case <-ticker.C:
-			h.prunePaths()
-		case <-h.stopCh:
-			return
-		}
-	}
-}
-
-// prunePaths removes AS paths older than pathExpirationTime
-func (h *PeeringHandler) prunePaths() {
-	cutoff := time.Now().Add(-pathExpirationTime)
-	var removed int
-
-	h.mu.Lock()
-	for pathKey, timestamp := range h.asPaths {
-		if timestamp.Before(cutoff) {
-			delete(h.asPaths, pathKey)
-			removed++
-		}
-	}
-	pathCount := len(h.asPaths)
-	h.mu.Unlock()
-
-	if removed > 0 {
-		h.logger.Debug("Pruned old AS paths", "removed", removed, "remaining", pathCount)
-	}
-}
-
 // ProcessPeeringsNow triggers immediate processing of all accumulated AS
 // paths into peering records. This bypasses the normal periodic processing
 // schedule and is primarily intended for testing purposes.
@@ -174,15 +143,16 @@ func (h *PeeringHandler) ProcessPeeringsNow() {
 
 // processPeerings extracts peerings from AS paths and writes to database
 func (h *PeeringHandler) processPeerings() {
-	// Take a snapshot of current AS paths
-	h.mu.RLock()
-	pathsCopy := make(map[string]time.Time, len(h.asPaths))
-	for k, v := range h.asPaths {
-		pathsCopy[k] = v
-	}
-	h.mu.RUnlock()
+	// Take the accumulated paths and replace the map with a fresh empty one
+	// under the lock. Each path is processed exactly once and the memory is
+	// released, so the map never grows past a single interval's traffic.
+	h.mu.Lock()
+	paths := h.asPaths
+	h.asPaths = make(map[string]time.Time)
+	dropped := h.droppedPaths
+	h.mu.Unlock()
 
-	if len(pathsCopy) == 0 {
+	if len(paths) == 0 {
 		return
 	}
 
@@ -192,7 +162,7 @@ func (h *PeeringHandler) processPeerings() {
 	}
 	peerings := make(map[peeringKey]time.Time)
 
-	for pathJSON, timestamp := range pathsCopy {
+	for pathJSON, timestamp := range paths {
 		var path []int
 		if err := json.Unmarshal([]byte(pathJSON), &path); err != nil {
 			h.logger.Error("Failed to decode AS path", "error", err)
@@ -241,15 +211,16 @@ func (h *PeeringHandler) processPeerings() {
 	}
 
 	h.logger.Info("Processed AS peerings",
-		"paths", len(pathsCopy),
+		"paths", len(paths),
 		"unique_peerings", len(peerings),
 		"success", successCount,
+		"dropped_paths", dropped,
 		"duration", time.Since(start),
 	)
 }
 
 // Stop gracefully shuts down the handler by signaling the background
-// goroutines to stop and performing a final synchronous processing of
+// goroutine to stop and performing a final synchronous processing of
 // any remaining AS paths. This ensures no peering data is lost during
 // shutdown.
 func (h *PeeringHandler) Stop() {

internal/routewatch/peeringhandler_test.go

@@ -0,0 +1,163 @@
+package routewatch
+
+import (
+	"encoding/json"
+	"strconv"
+	"sync"
+	"testing"
+	"time"
+
+	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/logger"
+	"git.eeqj.de/sneak/routewatch/internal/ristypes"
+)
+
+const (
+	testASNA = 64500
+	testASNB = 64501
+	testASNC = 64502
+)
+
+// recordingStore wraps mockStore to count every RecordPeering call, so a
+// test can tell how many times a peering was written across separate runs.
+type recordingStore struct {
+	*mockStore
+
+	mu    sync.Mutex
+	calls int
+}
+
+func (r *recordingStore) RecordPeering(asA, asB int, ts time.Time) error {
+	r.mu.Lock()
+	r.calls++
+	r.mu.Unlock()
+
+	return r.mockStore.RecordPeering(asA, asB, ts)
+}
+
+func (r *recordingStore) callCount() int {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	return r.calls
+}
+
+// newTestHandler builds a PeeringHandler without starting the periodic
+// processing goroutine, so tests drive processing explicitly.
+func newTestHandler(db database.Store) *PeeringHandler {
+	return &PeeringHandler{
+		db:      db,
+		logger:  logger.New(),
+		asPaths: make(map[string]time.Time),
+		stopCh:  make(chan struct{}),
+	}
+}
+
+func snapshot(h *PeeringHandler) (tracked, dropped int) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
+	return len(h.asPaths), h.droppedPaths
+}
+
+func pathKey(t *testing.T, asns ...int) string {
+	t.Helper()
+
+	b, err := json.Marshal(ristypes.ASPath(asns))
+	if err != nil {
+		t.Fatalf("failed to marshal path: %v", err)
+	}
+
+	return string(b)
+}
+
+func handle(h *PeeringHandler, ts time.Time, asns ...int) {
+	h.HandleMessage(&ristypes.RISMessage{
+		Path:            ristypes.ASPath(asns),
+		ParsedTimestamp: ts,
+	})
+}
+
+// TestPeeringHandlerProcessesEachRunAndEmpties verifies that a processing run
+// empties the path map (the swap) and that a path seen again after a run is
+// recorded in the next run too.
+func TestPeeringHandlerProcessesEachRunAndEmpties(t *testing.T) {
+	store := &recordingStore{mockStore: newMockStore()}
+	h := newTestHandler(store)
+
+	now := time.Now().UTC()
+
+	// Run 1: one path, one peering recorded, map emptied afterwards.
+	handle(h, now, testASNA, testASNB)
+	h.ProcessPeeringsNow()
+
+	if tracked, _ := snapshot(h); tracked != 0 {
+		t.Fatalf("map not empty after first run: %d paths remain", tracked)
+	}
+	if got := store.callCount(); got != 1 {
+		t.Fatalf("want 1 RecordPeering call after first run, got %d", got)
+	}
+
+	// Run 2: the same path again is recorded again (RecordPeering upserts).
+	handle(h, now.Add(time.Second), testASNA, testASNB)
+	h.ProcessPeeringsNow()
+
+	if tracked, _ := snapshot(h); tracked != 0 {
+		t.Fatalf("map not empty after second run: %d paths remain", tracked)
+	}
+	if got := store.callCount(); got != 2 {
+		t.Fatalf("want 2 RecordPeering calls after second run, got %d", got)
+	}
+}
+
+// TestPeeringHandlerCapDropsAndCounts verifies that a full map drops new paths
+// and counts them, while a path already tracked is refreshed rather than
+// dropped.
+func TestPeeringHandlerCapDropsAndCounts(t *testing.T) {
+	store := &recordingStore{mockStore: newMockStore()}
+	h := newTestHandler(store)
+
+	now := time.Now().UTC()
+
+	// Fill the map to exactly maxTrackedPaths, including one real path key so
+	// the "already tracked" branch can be exercised. The filler keys are never
+	// processed in this test, so their contents do not matter.
+	existing := pathKey(t, testASNA, testASNB)
+
+	h.mu.Lock()
+	h.asPaths[existing] = now
+	for i := 0; len(h.asPaths) < maxTrackedPaths; i++ {
+		h.asPaths[strconv.Itoa(i)] = now
+	}
+	h.mu.Unlock()
+
+	// A new path is dropped and counted because the map is full.
+	handle(h, now.Add(time.Second), testASNA, testASNC)
+
+	tracked, dropped := snapshot(h)
+	if tracked != maxTrackedPaths {
+		t.Fatalf("want map size %d after drop, got %d", maxTrackedPaths, tracked)
+	}
+	if dropped != 1 {
+		t.Fatalf("want dropped count 1, got %d", dropped)
+	}
+
+	// A path already tracked is refreshed, not dropped.
+	refreshed := now.Add(2 * time.Second)
+	handle(h, refreshed, testASNA, testASNB)
+
+	tracked, dropped = snapshot(h)
+	if tracked != maxTrackedPaths {
+		t.Fatalf("want map size %d after refresh, got %d", maxTrackedPaths, tracked)
+	}
+	if dropped != 1 {
+		t.Fatalf("want dropped count still 1 after refresh, got %d", dropped)
+	}
+
+	h.mu.Lock()
+	gotTS := h.asPaths[existing]
+	h.mu.Unlock()
+	if !gotTS.Equal(refreshed) {
+		t.Fatalf("existing path timestamp not refreshed: want %v, got %v", refreshed, gotTS)
+	}
+}

internal/routewatch/prefixhandler.go

@@ -2,6 +2,8 @@ package routewatch
 
 import (
 	"net"
+	"net/netip"
+	"slices"
 	"strings"
 	"sync"
 	"time"
@@ -14,13 +16,22 @@ import (
 )
 
 const (
-	// prefixHandlerQueueSize is the queue capacity for prefix tracking operations
-	// DO NOT set this higher than 100000 without explicit instructions
-	prefixHandlerQueueSize = 100000
+	// prefixHandlerQueueSize is the queue capacity for prefix tracking
+	// operations, about 4 seconds of feed at peak. The streamer drops updates
+	// rather than blocks when a queue is full (a STATE message waits for
+	// room), so this bounds memory. Batches still flush on a timer
+	// (prefixBatchTimeout).
+	prefixHandlerQueueSize = 20000
 
 	// prefixBatchSize is the number of prefix updates to batch together
 	prefixBatchSize = 25000
 
+	// prefixBatchMaxSize is the most prefix updates the batch holds while the
+	// flush goroutine writes the previous one: ten batches, about 60 MiB
+	// (README "Memory"). At this size HandleMessage waits until the flush
+	// goroutine takes the batch.
+	prefixBatchMaxSize = 250000
+
 	// prefixBatchTimeout is the maximum time to wait before flushing a batch
 	// DO NOT reduce this timeout - larger batches are more efficient
 	prefixBatchTimeout = 1 * time.Second
@@ -31,18 +42,24 @@ const (
 )
 
 // PrefixHandler tracks BGP prefixes and maintains a live routing table in the database.
-// Routes are added on announcement and deleted on withdrawal.
+// Routes are added on announcement and deleted on withdrawal, and all routes of
+// a peer are deleted when its BGP session goes down.
 type PrefixHandler struct {
 	db      database.Store
 	logger  *logger.Logger
 	metrics *metrics.Tracker
 
-	// Batching
-	mu        sync.Mutex
-	batch     []prefixUpdate
-	lastFlush time.Time
-	stopCh    chan struct{}
-	wg        sync.WaitGroup
+	// Batching. mu guards batch and peersDown only: the flush goroutine takes
+	// both under mu and writes them after releasing mu, so HandleMessage
+	// waits for a database write only while batch is at prefixBatchMaxSize.
+	mu          sync.Mutex
+	batch       []prefixUpdate
+	peersDown   []string      // peers whose BGP session went down since the batch was taken
+	batchTaken  sync.Cond     // signalled when the flush goroutine takes batch; its L is &mu
+	batchFullCh chan struct{} // wakes the flush goroutine when batch is full
+	lastFlush   time.Time     // used only by the flush goroutine
+	stopCh      chan struct{}
+	wg          sync.WaitGroup
 }
 
 type prefixUpdate struct {
@@ -57,12 +74,14 @@ type prefixUpdate struct {
 // NewPrefixHandler creates a new batched prefix tracking handler
 func NewPrefixHandler(db database.Store, logger *logger.Logger) *PrefixHandler {
 	h := &PrefixHandler{
-		db:        db,
-		logger:    logger,
-		batch:     make([]prefixUpdate, 0, prefixBatchSize),
-		lastFlush: time.Now(),
-		stopCh:    make(chan struct{}),
+		db:          db,
+		logger:      logger,
+		batch:       make([]prefixUpdate, 0, prefixBatchSize),
+		batchFullCh: make(chan struct{}, 1),
+		lastFlush:   time.Now(),
+		stopCh:      make(chan struct{}),
 	}
+	h.batchTaken.L = &h.mu
 
 	// Start the flush timer goroutine
 	h.wg.Add(1)
@@ -78,8 +97,9 @@ func (h *PrefixHandler) SetMetricsTracker(metrics *metrics.Tracker) {
 
 // WantsMessage returns true if this handler wants to process messages of the given type
 func (h *PrefixHandler) WantsMessage(messageType string) bool {
-	// We only care about UPDATE messages for the routing table
-	return messageType == "UPDATE"
+	// UPDATE messages change routes; a STATE message can say a peer's
+	// session went down, which removes all of its routes.
+	return messageType == ristypes.MessageTypeUpdate || messageType == ristypes.MessageTypeState
 }
 
 // QueueCapacity returns the desired queue capacity for this handler
@@ -90,6 +110,14 @@ func (h *PrefixHandler) QueueCapacity() int {
 
 // HandleMessage processes a message to track prefix information
 func (h *PrefixHandler) HandleMessage(msg *ristypes.RISMessage) {
+	if msg.Type == ristypes.MessageTypeState {
+		if msg.State == ristypes.StateDown {
+			h.peerSessionDown(msg.Peer)
+		}
+
+		return
+	}
+
 	// Use the pre-parsed timestamp
 	timestamp := msg.ParsedTimestamp
 
@@ -102,11 +130,35 @@ func (h *PrefixHandler) HandleMessage(msg *ristypes.RISMessage) {
 	h.mu.Lock()
 	defer h.mu.Unlock()
 
-	// Process announcements
+	// While the batch is at its maximum size, wait until the flush goroutine
+	// takes it. Meanwhile the handler takes nothing off its queue, which
+	// fills, and the streamer drops messages for it.
+	for len(h.batch) >= prefixBatchMaxSize {
+		h.batchTaken.Wait()
+	}
+
+	// Withdrawals are queued before announcements, because the batch keeps
+	// each peer's last update for a prefix: a message that lists a prefix as
+	// both withdrawn and announced keeps the route (RFC 4271 section 4.3).
+	// A withdrawal names only the prefix and peer: the message's AS path, and
+	// so its origin AS, belongs to the announced prefixes.
+	for _, prefix := range msg.Withdrawals {
+		h.batch = append(h.batch, prefixUpdate{
+			prefix:      canonicalPrefix(prefix),
+			peer:        msg.Peer,
+			messageType: "withdrawal",
+			timestamp:   timestamp,
+		})
+		// Record withdrawal in metrics
+		if h.metrics != nil {
+			h.metrics.RecordWithdrawal()
+		}
+	}
+
 	for _, announcement := range msg.Announcements {
 		for _, prefix := range announcement.Prefixes {
 			h.batch = append(h.batch, prefixUpdate{
-				prefix:      prefix,
+				prefix:      canonicalPrefix(prefix),
 				originASN:   originASN,
 				peer:        msg.Peer,
 				messageType: "announcement",
@@ -120,29 +172,32 @@ func (h *PrefixHandler) HandleMessage(msg *ristypes.RISMessage) {
 		}
 	}
 
-	// Process withdrawals
-	for _, prefix := range msg.Withdrawals {
-		h.batch = append(h.batch, prefixUpdate{
-			prefix:      prefix,
-			originASN:   originASN, // Use the originASN from path if available
-			peer:        msg.Peer,
-			messageType: "withdrawal",
-			timestamp:   timestamp,
-			path:        msg.Path,
-		})
-		// Record withdrawal in metrics
-		if h.metrics != nil {
-			h.metrics.RecordWithdrawal()
-		}
-	}
-
-	// Check if we need to flush
+	// A full batch wakes the flush goroutine. If it is writing, the wake-up
+	// waits in batchFullCh and the batch keeps growing until the write ends
+	// or the batch reaches prefixBatchMaxSize.
 	if len(h.batch) >= prefixBatchSize {
-		h.flushBatchLocked()
+		select {
+		case h.batchFullCh <- struct{}{}:
+		default: // already woken
+		}
 	}
 }
 
-// flushLoop runs in a goroutine and periodically flushes batches
+// peerSessionDown notes that the peer's BGP session went down, so that the next
+// flush deletes all of the peer's live routes before it writes the batch. The
+// peer's updates still in the batch came before the down, which replaces them,
+// so they are dropped; updates the peer sends later stay in the batch and are
+// written after the delete.
+func (h *PrefixHandler) peerSessionDown(peer string) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
+	h.batch = slices.DeleteFunc(h.batch, func(update prefixUpdate) bool { return update.peer == peer })
+	h.peersDown = append(h.peersDown, peer)
+}
+
+// flushLoop runs in a goroutine, the only one that writes the batch: it
+// flushes when the batch is full, periodically, and once more on Stop.
 func (h *PrefixHandler) flushLoop() {
 	defer h.wg.Done()
 	ticker := time.NewTicker(prefixBatchTimeout)
@@ -151,39 +206,75 @@ func (h *PrefixHandler) flushLoop() {
 	for {
 		select {
 		case <-ticker.C:
-			h.mu.Lock()
 			if time.Since(h.lastFlush) >= prefixBatchTimeout {
-				h.flushBatchLocked()
+				h.flushBatch()
 			}
-			h.mu.Unlock()
+		case <-h.batchFullCh:
+			h.flushBatch()
 		case <-h.stopCh:
 			// Final flush
-			h.mu.Lock()
-			h.flushBatchLocked()
-			h.mu.Unlock()
+			h.flushBatch()
 
 			return
 		}
 	}
 }
 
-// flushBatchLocked flushes the prefix batch to the database (must be called with mutex held)
-func (h *PrefixHandler) flushBatchLocked() {
-	if len(h.batch) == 0 {
+// takeBatch returns the pending updates and the peers whose session went down
+// since the last flush, and leaves an empty batch and no peers in their place
+// for HandleMessage to fill.
+func (h *PrefixHandler) takeBatch() ([]prefixUpdate, []string) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
+	if len(h.batch) == 0 && len(h.peersDown) == 0 {
+		return nil, nil
+	}
+	batch, peersDown := h.batch, h.peersDown
+	h.batch = make([]prefixUpdate, 0, prefixBatchSize)
+	h.peersDown = nil
+	h.batchTaken.Broadcast()
+
+	return batch, peersDown
+}
+
+// flushBatch takes the pending batch and writes it to the database, without
+// holding the mutex during the write.
+func (h *PrefixHandler) flushBatch() {
+	batch, peersDown := h.takeBatch()
+	if len(batch) == 0 && len(peersDown) == 0 {
 		return
 	}
 
 	startTime := time.Now()
-	batchSize := len(h.batch)
+	batchSize := len(batch)
 
-	// Group updates by prefix to deduplicate
-	// For each prefix, keep the latest update
-	prefixMap := make(map[string]prefixUpdate)
-	for _, update := range h.batch {
-		key := update.prefix
-		if existing, ok := prefixMap[key]; !ok || update.timestamp.After(existing.timestamp) {
-			prefixMap[key] = update
+	// The routes of a peer whose session went down are deleted first: the
+	// batch holds only the updates the peer sent after the down. Most downs
+	// come from peers that have no routes, so only a delete that removed
+	// routes is logged.
+	for _, peer := range peersDown {
+		deleted, err := h.db.DeleteLiveRoutesOfPeer(peer)
+		if err != nil {
+			h.logger.Error("Failed to delete the live routes of a peer whose session went down",
+				"peer", peer, "error", err)
+
+			continue
 		}
+		if deleted > 0 {
+			h.logger.Info("Deleted the live routes of a peer whose session went down",
+				"peer", peer, "routes", deleted)
+		}
+	}
+
+	// For each prefix and peer, keep only the last update the feed delivered.
+	// Updates from different peers for the same prefix are all kept. Arrival
+	// order decides, not the timestamp: timestamps are whole seconds, so
+	// updates within one second carry the same one.
+	type prefixAndPeer struct{ prefix, peer string }
+	lastUpdates := make(map[prefixAndPeer]prefixUpdate)
+	for _, update := range batch {
+		lastUpdates[prefixAndPeer{update.prefix, update.peer}] = update
 	}
 
 	// Collect routes to upsert and delete
@@ -193,7 +284,7 @@ func (h *PrefixHandler) flushBatchLocked() {
 	// Collect unique prefixes to update
 	prefixesToUpdate := make(map[string]time.Time)
 
-	for _, update := range prefixMap {
+	for _, update := range lastUpdates {
 		// Track prefix for both announcements and withdrawals
 		if _, exists := prefixesToUpdate[update.prefix]; !exists || update.timestamp.After(prefixesToUpdate[update.prefix]) {
 			prefixesToUpdate[update.prefix] = update.timestamp
@@ -217,7 +308,6 @@ func (h *PrefixHandler) flushBatchLocked() {
 			// Create deletion record for batch delete
 			routesToDelete = append(routesToDelete, database.LiveRouteDeletion{
 				Prefix:    update.prefix,
-				OriginASN: update.originASN,
 				PeerIP:    update.peer,
 				IPVersion: ipVersion,
 			})
@@ -252,16 +342,30 @@ func (h *PrefixHandler) flushBatchLocked() {
 	elapsed := time.Since(startTime)
 	h.logger.Debug("Flushed prefix batch",
 		"batch_size", batchSize,
-		"unique_prefixes", len(prefixMap),
+		"peers_down", len(peersDown),
+		"unique_prefixes", len(prefixesToUpdate),
 		"success", successCount,
 		"duration_ms", elapsed.Milliseconds(),
 	)
 
-	// Clear batch
-	h.batch = h.batch[:0]
 	h.lastFlush = time.Now()
 }
 
+// canonicalPrefix returns prefix in the text form net/netip prints, the form
+// the IP lookup builds when it looks a prefix up. The feed sends IPv6
+// announcements compressed ("2001:db8::/32") but IPv6 withdrawals uncompressed
+// ("2001:db8:0:0:0:0:0:0/32"); stored as received, a withdrawal would not match
+// the route its announcement stored. A prefix that does not parse is returned
+// unchanged, and the batch flush reports it.
+func canonicalPrefix(prefix string) string {
+	p, err := netip.ParsePrefix(prefix)
+	if err != nil {
+		return prefix
+	}
+
+	return p.Masked().String()
+}
+
 // parseCIDR extracts the mask length and IP version from a prefix string
 func parseCIDR(prefix string) (maskLength int, ipVersion int, err error) {
 	_, ipNet, err := net.ParseCIDR(prefix)
@@ -313,20 +417,6 @@ func (h *PrefixHandler) processAnnouncement(_ *database.Prefix, update prefixUpd
 		LastUpdated: update.timestamp,
 	}
 
-	// For IPv4, calculate the IP range
-	if ipVersion == ipv4Version {
-		start, end, err := database.CalculateIPv4Range(update.prefix)
-		if err == nil {
-			liveRoute.V4IPStart = &start
-			liveRoute.V4IPEnd = &end
-		} else {
-			h.logger.Error("Failed to calculate IPv4 range",
-				"prefix", update.prefix,
-				"error", err,
-			)
-		}
-	}
-
 	if err := h.db.UpsertLiveRoute(liveRoute); err != nil {
 		h.logger.Error("Failed to upsert live route",
 			"prefix", update.prefix,
@@ -370,20 +460,6 @@ func (h *PrefixHandler) createLiveRoute(update prefixUpdate) *database.LiveRoute
 		LastUpdated: update.timestamp,
 	}
 
-	// For IPv4, calculate the IP range
-	if ipVersion == ipv4Version {
-		start, end, err := database.CalculateIPv4Range(update.prefix)
-		if err == nil {
-			liveRoute.V4IPStart = &start
-			liveRoute.V4IPEnd = &end
-		} else {
-			h.logger.Error("Failed to calculate IPv4 range",
-				"prefix", update.prefix,
-				"error", err,
-			)
-		}
-	}
-
 	return liveRoute
 }
 
@@ -423,20 +499,6 @@ func (h *PrefixHandler) processAnnouncementDirect(update prefixUpdate) {
 		LastUpdated: update.timestamp,
 	}
 
-	// For IPv4, calculate the IP range
-	if ipVersion == ipv4Version {
-		start, end, err := database.CalculateIPv4Range(update.prefix)
-		if err == nil {
-			liveRoute.V4IPStart = &start
-			liveRoute.V4IPEnd = &end
-		} else {
-			h.logger.Error("Failed to calculate IPv4 range",
-				"prefix", update.prefix,
-				"error", err,
-			)
-		}
-	}
-
 	if err := h.db.UpsertLiveRoute(liveRoute); err != nil {
 		h.logger.Error("Failed to upsert live route",
 			"prefix", update.prefix,
@@ -448,51 +510,24 @@ func (h *PrefixHandler) processAnnouncementDirect(update prefixUpdate) {
 // processWithdrawalDirect handles removing a route directly without prefix table
 // nolint:unused // kept for potential future use
 func (h *PrefixHandler) processWithdrawalDirect(update prefixUpdate) {
-	// For withdrawals, we need to delete the route from live_routes
-	if update.originASN > 0 {
-		if err := h.db.DeleteLiveRoute(update.prefix, update.originASN, update.peer); err != nil {
-			h.logger.Error("Failed to delete live route",
-				"prefix", update.prefix,
-				"origin_asn", update.originASN,
-				"peer", update.peer,
-				"error", err,
-			)
-		}
-	} else {
-		// If no origin ASN, just delete all routes for this prefix from this peer
-		if err := h.db.DeleteLiveRoute(update.prefix, 0, update.peer); err != nil {
-			h.logger.Error("Failed to delete live route (no origin ASN)",
-				"prefix", update.prefix,
-				"peer", update.peer,
-				"error", err,
-			)
-		}
+	if err := h.db.DeleteLiveRoute(update.prefix, update.peer); err != nil {
+		h.logger.Error("Failed to delete live route",
+			"prefix", update.prefix,
+			"peer", update.peer,
+			"error", err,
+		)
 	}
 }
 
 // processWithdrawal handles removing a route from the live routing table
 // nolint:unused // kept for potential future use
 func (h *PrefixHandler) processWithdrawal(_ *database.Prefix, update prefixUpdate) {
-	// For withdrawals, we need to delete the route from live_routes
-	// Since we have the origin ASN from the update, we can delete the specific route
-	if update.originASN > 0 {
-		if err := h.db.DeleteLiveRoute(update.prefix, update.originASN, update.peer); err != nil {
-			h.logger.Error("Failed to delete live route",
-				"prefix", update.prefix,
-				"origin_asn", update.originASN,
-				"peer", update.peer,
-				"error", err,
-			)
-		}
-	} else {
-		// If no origin ASN, just delete all routes for this prefix from this peer
-		if err := h.db.DeleteLiveRoute(update.prefix, 0, update.peer); err != nil {
-			h.logger.Error("Failed to delete live route (no origin ASN)",
-				"prefix", update.prefix,
-				"peer", update.peer,
-				"error", err,
-			)
-		}
+	if err := h.db.DeleteLiveRoute(update.prefix, update.peer); err != nil {
+		h.logger.Error("Failed to delete live route",
+			"prefix", update.prefix,
+			"peer", update.peer,
+			"error", err,
+		)
 	}
 }
 

internal/routewatch/prefixhandler_test.go

@@ -0,0 +1,564 @@
+package routewatch
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"slices"
+	"sync"
+	"testing"
+	"time"
+
+	"git.eeqj.de/sneak/routewatch/internal/config"
+	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/logger"
+	"git.eeqj.de/sneak/routewatch/internal/ristypes"
+)
+
+const testPeerIP = "2001:db8:ffff::1"
+
+// TestPrefixHandlerStoresPrefixesTheIPLookupFinds runs announcements and
+// withdrawals through the prefix handler into a real database and looks the
+// addresses up. The prefixes are written the way the feed sends them: IPv6
+// announcements compressed, IPv6 withdrawals uncompressed. The withdrawal must
+// remove the route the announcement stored, and the IP lookup must find the
+// stored prefix.
+func TestPrefixHandlerStoresPrefixesTheIPLookupFinds(t *testing.T) {
+	db, err := database.New(&config.Config{StateDir: t.TempDir()}, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	// Built without NewPrefixHandler's flush timer, so the test flushes itself.
+	h := &PrefixHandler{db: db, logger: logger.New()}
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	h.HandleMessage(&ristypes.RISMessage{
+		Peer:            testPeerIP,
+		Path:            ristypes.ASPath{testASNA, testASNB},
+		ParsedTimestamp: ts,
+		Announcements: []ristypes.RISAnnouncement{{
+			NextHop:  testPeerIP,
+			Prefixes: []string{"2001:db8:1::/48", "192.0.2.0/24"},
+		}},
+	})
+	h.flushBatch()
+
+	for ip, want := range map[string]string{
+		"2001:db8:1::1": "2001:db8:1::/48",
+		"192.0.2.1":     "192.0.2.0/24",
+	} {
+		info, err := db.GetIPInfo(ip)
+		if err != nil {
+			t.Fatalf("GetIPInfo(%s) after announcement: %v", ip, err)
+		}
+		if info.Netblock != want || info.ASN != testASNB {
+			t.Errorf("GetIPInfo(%s) = %s AS%d, want %s AS%d", ip, info.Netblock, info.ASN, want, testASNB)
+		}
+	}
+
+	h.HandleMessage(&ristypes.RISMessage{
+		Peer:            testPeerIP,
+		ParsedTimestamp: ts.Add(time.Minute),
+		Withdrawals:     []string{"2001:db8:1:0:0:0:0:0/48", "192.0.2.0/24"},
+	})
+	h.flushBatch()
+
+	for _, ip := range []string{"2001:db8:1::1", "192.0.2.1"} {
+		if info, err := db.GetIPInfo(ip); !errors.Is(err, database.ErrNoRoute) {
+			t.Errorf("GetIPInfo(%s) after withdrawal = %+v, %v; want ErrNoRoute", ip, info, err)
+		}
+	}
+}
+
+// TestPrefixHandlerAppliesEachPeersLastUpdateInABatch runs updates for one
+// prefix through the prefix handler into a real database. All updates carry the
+// same timestamp, as updates within one second of the feed do. Within a batch,
+// the last update each peer sent for the prefix decides whether that peer has a
+// live route for it, and updates from different peers are all applied. The
+// in-memory route count and prefix distribution must match the route table.
+func TestPrefixHandlerAppliesEachPeersLastUpdateInABatch(t *testing.T) {
+	const (
+		prefix           = "198.51.100.0/24"
+		prefixMaskLength = 24
+		otherPeerIP      = "2001:db8:ffff::2"
+	)
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	announce := func(peer string) *ristypes.RISMessage {
+		return &ristypes.RISMessage{
+			Peer:            peer,
+			Path:            ristypes.ASPath{testASNA, testASNB},
+			ParsedTimestamp: ts,
+			Announcements:   []ristypes.RISAnnouncement{{NextHop: peer, Prefixes: []string{prefix}}},
+		}
+	}
+	withdraw := func(peer string) *ristypes.RISMessage {
+		return &ristypes.RISMessage{Peer: peer, ParsedTimestamp: ts, Withdrawals: []string{prefix}}
+	}
+	announceAndWithdraw := func(peer string) *ristypes.RISMessage {
+		msg := announce(peer)
+		msg.Withdrawals = []string{prefix}
+
+		return msg
+	}
+
+	tests := []struct {
+		name string
+		// Each inner list is handled and then flushed as one batch.
+		batches [][]*ristypes.RISMessage
+		// The peers left with a live route for the prefix, by peer IP.
+		wantPeers []string
+	}{
+		{
+			name:      "two peers announce the prefix",
+			batches:   [][]*ristypes.RISMessage{{announce(testPeerIP), announce(otherPeerIP)}},
+			wantPeers: []string{testPeerIP, otherPeerIP},
+		},
+		{
+			name: "two peers withdraw the prefix",
+			batches: [][]*ristypes.RISMessage{
+				{announce(testPeerIP)},
+				{announce(otherPeerIP)},
+				{withdraw(testPeerIP), withdraw(otherPeerIP)},
+			},
+		},
+		{
+			name:    "a peer announces and then withdraws the prefix",
+			batches: [][]*ristypes.RISMessage{{announce(testPeerIP), withdraw(testPeerIP)}},
+		},
+		{
+			name: "a peer withdraws and then re-announces the prefix",
+			batches: [][]*ristypes.RISMessage{
+				{announce(testPeerIP)},
+				{withdraw(testPeerIP), announce(testPeerIP)},
+			},
+			wantPeers: []string{testPeerIP},
+		},
+		{
+			// RFC 4271 section 4.3: the announcement counts, not the withdrawal.
+			name: "one message announces and withdraws the prefix",
+			batches: [][]*ristypes.RISMessage{
+				{announce(testPeerIP)},
+				{announceAndWithdraw(testPeerIP)},
+			},
+			wantPeers: []string{testPeerIP},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			db, err := database.New(&config.Config{StateDir: t.TempDir()}, logger.New())
+			if err != nil {
+				t.Fatalf("failed to create database: %v", err)
+			}
+			defer func() { _ = db.Close() }()
+
+			// Built without NewPrefixHandler's flush timer, so the test flushes itself.
+			h := &PrefixHandler{db: db, logger: logger.New()}
+			for _, batch := range tt.batches {
+				for _, msg := range batch {
+					h.HandleMessage(msg)
+				}
+				h.flushBatch()
+			}
+
+			ctx := context.Background()
+			routes, _, err := db.GetPrefixDetailsContext(ctx, prefix)
+			if err != nil && !errors.Is(err, database.ErrNoRoute) {
+				t.Fatalf("GetPrefixDetailsContext: %v", err)
+			}
+			var gotPeers []string
+			for _, route := range routes {
+				gotPeers = append(gotPeers, route.PeerIP)
+			}
+			if !slices.Equal(gotPeers, tt.wantPeers) {
+				t.Errorf("peers with a live route for %s = %v, want %v", prefix, gotPeers, tt.wantPeers)
+			}
+
+			var wantDistribution []database.PrefixDistribution
+			if len(tt.wantPeers) > 0 {
+				wantDistribution = []database.PrefixDistribution{{MaskLength: prefixMaskLength, Count: 1}}
+			}
+			assertCounts(t, db, ipv4Version, len(tt.wantPeers), wantDistribution)
+		})
+	}
+}
+
+// TestPrefixHandlerKeepsOneRoutePerPrefixAndPeer runs updates from one peer
+// through the prefix handler into a real database, flushing each message as its
+// own batch, once with IPv4 prefixes and once with IPv6 prefixes. A peer has at
+// most one route for a prefix: a later announcement replaces it whatever its
+// origin AS, and a withdrawal removes it whatever AS the message's AS path ends
+// in. The in-memory route count and prefix distribution must match the route
+// table.
+func TestPrefixHandlerKeepsOneRoutePerPrefixAndPeer(t *testing.T) {
+	families := []struct {
+		ipVersion           int
+		prefix, otherPrefix string
+		// The mask length of both prefixes.
+		maskLength int
+	}{
+		{ipVersion: ipv4Version, prefix: "198.51.100.0/24", otherPrefix: "203.0.113.0/24", maskLength: 24},
+		{ipVersion: ipv6Version, prefix: "2001:db8:1::/48", otherPrefix: "2001:db8:2::/48", maskLength: 48},
+	}
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	announce := func(path ristypes.ASPath, announced string) *ristypes.RISMessage {
+		return &ristypes.RISMessage{
+			Peer:            testPeerIP,
+			Path:            path,
+			ParsedTimestamp: ts,
+			Announcements:   []ristypes.RISAnnouncement{{NextHop: testPeerIP, Prefixes: []string{announced}}},
+		}
+	}
+
+	for _, family := range families {
+		prefix, otherPrefix := family.prefix, family.otherPrefix
+
+		// One message that announces otherPrefix with origin AS testASNB and
+		// withdraws prefix.
+		announceOtherAndWithdraw := announce(ristypes.ASPath{testASNA, testASNB}, otherPrefix)
+		announceOtherAndWithdraw.Withdrawals = []string{prefix}
+
+		tests := []struct {
+			name     string
+			messages []*ristypes.RISMessage
+			// The origin AS of the peer's live route for each prefix. A prefix
+			// left out must have no live route.
+			wantOrigins map[string]int
+		}{
+			{
+				name: "the peer announces the prefix with a new origin AS",
+				messages: []*ristypes.RISMessage{
+					announce(ristypes.ASPath{testASNA}, prefix),
+					announce(ristypes.ASPath{testASNA, testASNB}, prefix),
+				},
+				wantOrigins: map[string]int{prefix: testASNB},
+			},
+			{
+				name: "one message announces a prefix with another origin AS and withdraws the prefix",
+				messages: []*ristypes.RISMessage{
+					announce(ristypes.ASPath{testASNA}, prefix),
+					announceOtherAndWithdraw,
+				},
+				wantOrigins: map[string]int{otherPrefix: testASNB},
+			},
+		}
+
+		for _, tt := range tests {
+			t.Run(fmt.Sprintf("IPv%d %s", family.ipVersion, tt.name), func(t *testing.T) {
+				db, err := database.New(&config.Config{StateDir: t.TempDir()}, logger.New())
+				if err != nil {
+					t.Fatalf("failed to create database: %v", err)
+				}
+				defer func() { _ = db.Close() }()
+
+				// Built without NewPrefixHandler's flush timer, so the test flushes itself.
+				h := &PrefixHandler{db: db, logger: logger.New()}
+				for _, msg := range tt.messages {
+					h.HandleMessage(msg)
+					h.flushBatch()
+				}
+
+				for _, p := range []string{prefix, otherPrefix} {
+					routes, _, err := db.GetPrefixDetailsContext(context.Background(), p)
+					if err != nil && !errors.Is(err, database.ErrNoRoute) {
+						t.Fatalf("GetPrefixDetailsContext(%s): %v", p, err)
+					}
+					var gotOrigins []int
+					for _, route := range routes {
+						gotOrigins = append(gotOrigins, route.OriginASN)
+					}
+					var wantOrigins []int
+					if origin, ok := tt.wantOrigins[p]; ok {
+						wantOrigins = []int{origin}
+					}
+					if !slices.Equal(gotOrigins, wantOrigins) {
+						t.Errorf("origin ASes of the live routes for %s = %v, want %v", p, gotOrigins, wantOrigins)
+					}
+				}
+
+				wantDistribution := []database.PrefixDistribution{
+					{MaskLength: family.maskLength, Count: len(tt.wantOrigins)},
+				}
+				assertCounts(t, db, family.ipVersion, len(tt.wantOrigins), wantDistribution)
+			})
+		}
+	}
+}
+
+// TestPrefixHandlerDeletesAPeersRoutesWhenItsSessionGoesDown runs
+// announcements from two peers through the prefix handler into a real
+// database, then a batch in which one of the peers announces a prefix and its
+// session goes down. The down deletes every live route of that peer, IPv4 and
+// IPv6, the one announced just before it included, and keeps the other peer's
+// routes for the same prefixes. An announcement the peer sends after the down,
+// in the same batch, is kept. The in-memory route counts and prefix
+// distribution must match the route tables.
+func TestPrefixHandlerDeletesAPeersRoutesWhenItsSessionGoesDown(t *testing.T) {
+	const (
+		otherPeerIP = "2001:db8:ffff::2"
+		// Both peers announce the shared prefixes, only testPeerIP the others.
+		sharedV4   = "198.51.100.0/24"
+		sharedV6   = "2001:db8:1::/48"
+		onlyV4     = "203.0.113.0/24"
+		onlyV6     = "2001:db8:2::/48"
+		beforeDown = "192.0.2.0/24"
+		afterDown  = "2001:db8:3::/48"
+		// The mask lengths of the IPv4 and of the IPv6 prefixes.
+		maskLengthV4 = 24
+		maskLengthV6 = 48
+	)
+
+	tests := []struct {
+		name string
+		// Handled and flushed as one batch after both peers' announcements.
+		batch []*ristypes.RISMessage
+		// Whether testPeerIP is left with a live route for afterDown.
+		wantAfterDown bool
+	}{
+		{
+			name:  "the down ends the batch",
+			batch: []*ristypes.RISMessage{peerAnnouncement(testPeerIP, beforeDown), sessionDown(testPeerIP)},
+		},
+		{
+			name: "the peer announces a prefix after the down",
+			batch: []*ristypes.RISMessage{
+				peerAnnouncement(testPeerIP, beforeDown),
+				sessionDown(testPeerIP),
+				peerAnnouncement(testPeerIP, afterDown),
+			},
+			wantAfterDown: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			db, err := database.New(&config.Config{StateDir: t.TempDir()}, logger.New())
+			if err != nil {
+				t.Fatalf("failed to create database: %v", err)
+			}
+			defer func() { _ = db.Close() }()
+
+			// Built without NewPrefixHandler's flush timer, so the test flushes itself.
+			h := &PrefixHandler{db: db, logger: logger.New()}
+			h.HandleMessage(peerAnnouncement(testPeerIP, sharedV4, sharedV6, onlyV4, onlyV6))
+			h.HandleMessage(peerAnnouncement(otherPeerIP, sharedV4, sharedV6))
+			h.flushBatch()
+			for _, msg := range tt.batch {
+				h.HandleMessage(msg)
+			}
+			h.flushBatch()
+
+			// The peers left with a live route for each prefix.
+			wantPeers := map[string][]string{
+				sharedV4:   {otherPeerIP},
+				sharedV6:   {otherPeerIP},
+				onlyV4:     nil,
+				onlyV6:     nil,
+				beforeDown: nil,
+				afterDown:  nil,
+			}
+			wantRoutesV6 := 1
+			if tt.wantAfterDown {
+				wantPeers[afterDown] = []string{testPeerIP}
+				wantRoutesV6++
+			}
+
+			assertPeers(t, db, wantPeers)
+			assertCounts(t, db, ipv4Version, 1,
+				[]database.PrefixDistribution{{MaskLength: maskLengthV4, Count: 1}})
+			assertCounts(t, db, ipv6Version, wantRoutesV6,
+				[]database.PrefixDistribution{{MaskLength: maskLengthV6, Count: wantRoutesV6}})
+		})
+	}
+}
+
+// TestPrefixHandlerKeepsWhatAPeerAnnouncesAfterTheFlushOfItsDown runs, through
+// the prefix handler into a real database, one flush after another: a peer's
+// announcement, its session going down, a new announcement from the peer, and
+// another peer's announcement. The down deletes the peer's routes on the flush
+// that handles it and on no later flush, so the route the peer announced after
+// it is kept.
+func TestPrefixHandlerKeepsWhatAPeerAnnouncesAfterTheFlushOfItsDown(t *testing.T) {
+	const (
+		otherPeerIP = "2001:db8:ffff::2"
+		beforeDown  = "192.0.2.0/24"
+		afterDown   = "198.51.100.0/24"
+		otherPeers  = "203.0.113.0/24"
+		maskLength  = 24
+	)
+
+	db, err := database.New(&config.Config{StateDir: t.TempDir()}, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	// Built without NewPrefixHandler's flush timer, so the test flushes itself.
+	h := &PrefixHandler{db: db, logger: logger.New()}
+	for _, msg := range []*ristypes.RISMessage{
+		peerAnnouncement(testPeerIP, beforeDown),
+		sessionDown(testPeerIP),
+		peerAnnouncement(testPeerIP, afterDown),
+		peerAnnouncement(otherPeerIP, otherPeers),
+	} {
+		h.HandleMessage(msg)
+		h.flushBatch()
+	}
+
+	assertPeers(t, db, map[string][]string{
+		beforeDown: nil,
+		afterDown:  {testPeerIP},
+		otherPeers: {otherPeerIP},
+	})
+	assertCounts(t, db, ipv4Version, 2, []database.PrefixDistribution{{MaskLength: maskLength, Count: 2}})
+}
+
+// firstWriteHeldStore is a real database whose first live route batch write
+// waits until the test closes release. writeStarted is closed when it starts.
+type firstWriteHeldStore struct {
+	*database.Database
+
+	writeStarted chan struct{}
+	release      chan struct{}
+	once         sync.Once
+}
+
+func (s *firstWriteHeldStore) UpsertLiveRouteBatch(routes []*database.LiveRoute) error {
+	s.once.Do(func() {
+		close(s.writeStarted)
+		<-s.release
+	})
+
+	return s.Database.UpsertLiveRouteBatch(routes)
+}
+
+// TestPrefixHandlerHandlesADownWhileAFlushWrites holds the write of a flush
+// that stores a peer's route and meanwhile hands the prefix handler the peer's
+// session going down, then a new announcement from the peer. The next flush
+// must delete the route the held write stored and keep the one announced after
+// the down.
+func TestPrefixHandlerHandlesADownWhileAFlushWrites(t *testing.T) {
+	const (
+		beforeDown = "192.0.2.0/24"
+		afterDown  = "198.51.100.0/24"
+		maskLength = 24
+	)
+
+	db, err := database.New(&config.Config{StateDir: t.TempDir()}, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+	store := &firstWriteHeldStore{Database: db, writeStarted: make(chan struct{}), release: make(chan struct{})}
+
+	// Built without NewPrefixHandler's flush timer, so the test flushes itself.
+	h := &PrefixHandler{db: store, logger: logger.New()}
+	h.HandleMessage(peerAnnouncement(testPeerIP, beforeDown))
+	flushed := make(chan struct{})
+	go func() {
+		h.flushBatch()
+		close(flushed)
+	}()
+	select {
+	case <-store.writeStarted:
+	case <-time.After(handleMessageTimeout):
+		t.Fatal("the flush did not start its write")
+	}
+
+	if !returnsInTime(func() {
+		h.HandleMessage(sessionDown(testPeerIP))
+		h.HandleMessage(peerAnnouncement(testPeerIP, afterDown))
+	}) {
+		t.Fatal("HandleMessage did not return while a database write was held")
+	}
+	close(store.release)
+	select {
+	case <-flushed:
+	case <-time.After(handleMessageTimeout):
+		t.Fatal("the flush did not finish after its write was let go")
+	}
+	h.flushBatch()
+
+	assertPeers(t, db, map[string][]string{beforeDown: nil, afterDown: {testPeerIP}})
+	assertCounts(t, db, ipv4Version, 1, []database.PrefixDistribution{{MaskLength: maskLength, Count: 1}})
+}
+
+// peerAnnouncement returns an UPDATE message in which peer announces prefixes
+// with origin AS testASNB.
+func peerAnnouncement(peer string, prefixes ...string) *ristypes.RISMessage {
+	return &ristypes.RISMessage{
+		Type:            ristypes.MessageTypeUpdate,
+		Peer:            peer,
+		Path:            ristypes.ASPath{testASNA, testASNB},
+		ParsedTimestamp: time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC),
+		Announcements:   []ristypes.RISAnnouncement{{NextHop: peer, Prefixes: prefixes}},
+	}
+}
+
+// sessionDown returns the STATE message that says peer's BGP session went down.
+func sessionDown(peer string) *ristypes.RISMessage {
+	return &ristypes.RISMessage{Type: ristypes.MessageTypeState, Peer: peer, State: ristypes.StateDown}
+}
+
+// assertPeers checks, for each prefix in wantPeers, that the peers with a live
+// route for it are the ones listed, in peer IP order; nil means none.
+func assertPeers(t *testing.T, db *database.Database, wantPeers map[string][]string) {
+	t.Helper()
+
+	for prefix, want := range wantPeers {
+		routes, _, err := db.GetPrefixDetailsContext(context.Background(), prefix)
+		if err != nil && !errors.Is(err, database.ErrNoRoute) {
+			t.Fatalf("GetPrefixDetailsContext(%s): %v", prefix, err)
+		}
+		var got []string
+		for _, route := range routes {
+			got = append(got, route.PeerIP)
+		}
+		if !slices.Equal(got, want) {
+			t.Errorf("peers with a live route for %s = %v, want %v", prefix, got, want)
+		}
+	}
+}
+
+// assertCounts checks that the live route count and prefix distribution of one
+// IP version are wantRoutes and wantDistribution, both as held in memory and as
+// read from the route table.
+func assertCounts(t *testing.T, db *database.Database, ipVersion, wantRoutes int,
+	wantDistribution []database.PrefixDistribution) {
+	t.Helper()
+
+	ctx := context.Background()
+	stats, err := db.GetStatsContext(ctx)
+	if err != nil {
+		t.Fatalf("GetStatsContext: %v", err)
+	}
+	tableRoutesV4, tableRoutesV6, err := db.GetLiveRouteCountsContext(ctx)
+	if err != nil {
+		t.Fatalf("GetLiveRouteCountsContext: %v", err)
+	}
+	queryDistributionV4, queryDistributionV6, err := db.GetPrefixDistributionContext(ctx)
+	if err != nil {
+		t.Fatalf("GetPrefixDistributionContext: %v", err)
+	}
+
+	memoryRoutes, tableRoutes := stats.IPv4Routes, tableRoutesV4
+	memoryDistribution, queryDistribution := stats.IPv4PrefixDistribution, queryDistributionV4
+	if ipVersion == ipv6Version {
+		memoryRoutes, tableRoutes = stats.IPv6Routes, tableRoutesV6
+		memoryDistribution, queryDistribution = stats.IPv6PrefixDistribution, queryDistributionV6
+	}
+
+	if memoryRoutes != wantRoutes || tableRoutes != wantRoutes {
+		t.Errorf("IPv%d live routes: %d in memory, %d in the table, want %d",
+			ipVersion, memoryRoutes, tableRoutes, wantRoutes)
+	}
+	if !slices.Equal(memoryDistribution, wantDistribution) ||
+		!slices.Equal(queryDistribution, wantDistribution) {
+		t.Errorf("IPv%d prefix distribution: %v in memory, %v from the table, want %v",
+			ipVersion, memoryDistribution, queryDistribution, wantDistribution)
+	}
+}

internal/server/handlers.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"net"
 	"net/http"
+	"net/netip"
 	"runtime"
 	"sort"
 	"strconv"
@@ -179,9 +180,11 @@ func (s *Server) handleStatusJSON() http.HandlerFunc {
 
 		metrics := s.streamer.GetMetrics()
 
-		// Get database stats with timeout
-		statsChan := make(chan database.Stats)
-		errChan := make(chan error)
+		// Get database stats with timeout. The channels are buffered so the
+		// goroutine's send never blocks if the timeout wins and nothing here
+		// receives; otherwise it would block forever and leak.
+		statsChan := make(chan database.Stats, 1)
+		errChan := make(chan error, 1)
 
 		go func() {
 			dbStats, err := s.db.GetStatsContext(ctx)
@@ -195,19 +198,24 @@ func (s *Server) handleStatusJSON() http.HandlerFunc {
 		}()
 
 		var dbStats database.Stats
+		var err error
 		select {
 		case <-ctx.Done():
+			err = ctx.Err()
+		case err = <-errChan:
+		case dbStats = <-statsChan:
+		}
+		if deadlinePassed(ctx) {
 			s.logger.Error("Database stats timeout in status.json")
-			writeJSONError(w, http.StatusRequestTimeout, "Database timeout")
+			writeJSONError(w, http.StatusGatewayTimeout, requestTimeoutMessage)
 
 			return
-		case err := <-errChan:
+		}
+		if err != nil {
 			s.logger.Error("Failed to get database stats", "error", err)
 			writeJSONError(w, http.StatusInternalServerError, err.Error())
 
 			return
-		case dbStats = <-statsChan:
-			// Success
 		}
 
 		uptime := time.Since(metrics.ConnectedSince).Truncate(time.Second).String()
@@ -217,13 +225,6 @@ func (s *Server) handleStatusJSON() http.HandlerFunc {
 
 		const bitsPerMegabit = 1000000.0
 
-		// Get route counts from database
-		ipv4Routes, ipv6Routes, err := s.db.GetLiveRouteCountsContext(ctx)
-		if err != nil {
-			s.logger.Warn("Failed to get live route counts", "error", err)
-			// Continue with zero counts
-		}
-
 		// Get route update metrics
 		routeMetrics := s.streamer.GetMetricsTracker().GetRouteMetrics()
 
@@ -235,6 +236,11 @@ func (s *Server) handleStatusJSON() http.HandlerFunc {
 		var whoisStats *WHOISStatsInfo
 		if s.asnFetcher != nil {
 			whoisStats = s.getWHOISStats(ctx)
+			if deadlinePassed(ctx) {
+				writeJSONError(w, http.StatusGatewayTimeout, requestTimeoutMessage)
+
+				return
+			}
 		}
 
 		stats := Stats{
@@ -257,8 +263,8 @@ func (s *Server) handleStatusJSON() http.HandlerFunc {
 			Peers:                  dbStats.Peers,
 			DatabaseSizeBytes:      dbStats.FileSizeBytes,
 			LiveRoutes:             dbStats.LiveRoutes,
-			IPv4Routes:             ipv4Routes,
-			IPv6Routes:             ipv6Routes,
+			IPv4Routes:             dbStats.IPv4Routes,
+			IPv6Routes:             dbStats.IPv6Routes,
 			OldestRoute:            dbStats.OldestRoute,
 			NewestRoute:            dbStats.NewestRoute,
 			IPv4UpdatesPerSec:      routeMetrics.IPv4UpdatesPerSec,
@@ -390,7 +396,7 @@ func (s *Server) handleStats() http.HandlerFunc {
 		// Check if context is already cancelled
 		select {
 		case <-ctx.Done():
-			http.Error(w, "Request timeout", http.StatusRequestTimeout)
+			writeJSONError(w, http.StatusGatewayTimeout, requestTimeoutMessage)
 
 			return
 		default:
@@ -398,9 +404,11 @@ func (s *Server) handleStats() http.HandlerFunc {
 
 		metrics := s.streamer.GetMetrics()
 
-		// Get database stats with timeout
-		statsChan := make(chan database.Stats)
-		errChan := make(chan error)
+		// Get database stats with timeout. The channels are buffered so the
+		// goroutine's send never blocks if the timeout wins and nothing here
+		// receives; otherwise it would block forever and leak.
+		statsChan := make(chan database.Stats, 1)
+		errChan := make(chan error, 1)
 
 		go func() {
 			dbStats, err := s.db.GetStatsContext(ctx)
@@ -414,18 +422,24 @@ func (s *Server) handleStats() http.HandlerFunc {
 		}()
 
 		var dbStats database.Stats
+		var err error
 		select {
 		case <-ctx.Done():
+			err = ctx.Err()
+		case err = <-errChan:
+		case dbStats = <-statsChan:
+		}
+		if deadlinePassed(ctx) {
 			s.logger.Error("Database stats timeout")
-			// Don't write response here - timeout middleware already handles it
+			writeJSONError(w, http.StatusGatewayTimeout, requestTimeoutMessage)
+
 			return
-		case err := <-errChan:
+		}
+		if err != nil {
 			s.logger.Error("Failed to get database stats", "error", err)
 			writeJSONError(w, http.StatusInternalServerError, err.Error())
 
 			return
-		case dbStats = <-statsChan:
-			// Success
 		}
 
 		uptime := time.Since(metrics.ConnectedSince).Truncate(time.Second).String()
@@ -435,13 +449,6 @@ func (s *Server) handleStats() http.HandlerFunc {
 
 		const bitsPerMegabit = 1000000.0
 
-		// Get route counts from database
-		ipv4Routes, ipv6Routes, err := s.db.GetLiveRouteCountsContext(ctx)
-		if err != nil {
-			s.logger.Warn("Failed to get live route counts", "error", err)
-			// Continue with zero counts
-		}
-
 		// Get route update metrics
 		routeMetrics := s.streamer.GetMetricsTracker().GetRouteMetrics()
 
@@ -471,6 +478,11 @@ func (s *Server) handleStats() http.HandlerFunc {
 		var whoisStats *WHOISStatsInfo
 		if s.asnFetcher != nil {
 			whoisStats = s.getWHOISStats(ctx)
+			if deadlinePassed(ctx) {
+				writeJSONError(w, http.StatusGatewayTimeout, requestTimeoutMessage)
+
+				return
+			}
 		}
 
 		// Calculate connection duration
@@ -533,8 +545,8 @@ func (s *Server) handleStats() http.HandlerFunc {
 			Peers:                  dbStats.Peers,
 			DatabaseSizeBytes:      dbStats.FileSizeBytes,
 			LiveRoutes:             dbStats.LiveRoutes,
-			IPv4Routes:             ipv4Routes,
-			IPv6Routes:             ipv6Routes,
+			IPv4Routes:             dbStats.IPv4Routes,
+			IPv6Routes:             dbStats.IPv6Routes,
 			OldestRoute:            dbStats.OldestRoute,
 			NewestRoute:            dbStats.NewestRoute,
 			IPv4UpdatesPerSec:      routeMetrics.IPv4UpdatesPerSec,
@@ -622,6 +634,11 @@ func (s *Server) handleIPInfo() http.HandlerFunc {
 			} else {
 				// It's a hostname - resolve it
 				resolved, err := net.DefaultResolver.LookupHost(ctx, t)
+				if deadlinePassed(ctx) {
+					writeJSONError(w, http.StatusGatewayTimeout, requestTimeoutMessage)
+
+					return
+				}
 				if err != nil {
 					response.Errors = append(response.Errors, t+": "+err.Error())
 
@@ -643,6 +660,11 @@ func (s *Server) handleIPInfo() http.HandlerFunc {
 		// Look up each IP
 		for _, ip := range ipsToLookup {
 			ipInfo, err := s.db.GetIPInfoContext(ctx, ip)
+			if deadlinePassed(ctx) {
+				writeJSONError(w, http.StatusGatewayTimeout, requestTimeoutMessage)
+
+				return
+			}
 			if err != nil {
 				response.Errors = append(response.Errors, ip+": "+err.Error())
 
@@ -651,6 +673,11 @@ func (s *Server) handleIPInfo() http.HandlerFunc {
 
 			// Do PTR lookup for this IP
 			ptrs, err := net.DefaultResolver.LookupAddr(ctx, ip)
+			if deadlinePassed(ctx) {
+				writeJSONError(w, http.StatusGatewayTimeout, requestTimeoutMessage)
+
+				return
+			}
 			if err == nil && len(ptrs) > 0 {
 				// Remove trailing dots from PTR records
 				for i, ptr := range ptrs {
@@ -711,6 +738,11 @@ func (s *Server) handleASDetailJSON() http.HandlerFunc {
 		}
 
 		asInfo, prefixes, err := s.db.GetASDetailsContext(r.Context(), asn)
+		if deadlinePassed(r.Context()) {
+			writeJSONError(w, http.StatusGatewayTimeout, requestTimeoutMessage)
+
+			return
+		}
 		if err != nil {
 			if errors.Is(err, database.ErrNoRoute) {
 				writeJSONError(w, http.StatusNotFound, err.Error())
@@ -758,10 +790,22 @@ func (s *Server) handlePrefixDetailJSON() http.HandlerFunc {
 			return
 		}
 
-		// Combine prefix and length into CIDR notation
-		prefix := prefixParam + "/" + lenParam
+		// Look the prefix up in the text form net/netip prints, the form the
+		// tables store, so that any valid way of writing it finds the route.
+		parsed, err := netip.ParsePrefix(prefixParam + "/" + lenParam)
+		if err != nil {
+			writeJSONError(w, http.StatusBadRequest, err.Error())
 
-		routes, err := s.db.GetPrefixDetailsContext(r.Context(), prefix)
+			return
+		}
+		prefix := parsed.Masked().String()
+
+		routes, _, err := s.db.GetPrefixDetailsContext(r.Context(), prefix)
+		if deadlinePassed(r.Context()) {
+			writeJSONError(w, http.StatusGatewayTimeout, requestTimeoutMessage)
+
+			return
+		}
 		if err != nil {
 			if errors.Is(err, database.ErrNoRoute) {
 				writeJSONError(w, http.StatusNotFound, err.Error())
@@ -804,6 +848,11 @@ func (s *Server) handleASDetail() http.HandlerFunc {
 		}
 
 		asInfo, prefixes, err := s.db.GetASDetailsContext(r.Context(), asn)
+		if deadlinePassed(r.Context()) {
+			http.Error(w, requestTimeoutMessage, http.StatusGatewayTimeout)
+
+			return
+		}
 		if err != nil {
 			if errors.Is(err, database.ErrNoRoute) {
 				http.Error(w, "AS not found", http.StatusNotFound)
@@ -817,6 +866,11 @@ func (s *Server) handleASDetail() http.HandlerFunc {
 
 		// Get peers
 		peers, err := s.db.GetASPeersContext(r.Context(), asn)
+		if deadlinePassed(r.Context()) {
+			http.Error(w, requestTimeoutMessage, http.StatusGatewayTimeout)
+
+			return
+		}
 		if err != nil {
 			s.logger.Error("Failed to get AS peers", "error", err)
 			// Continue without peers rather than failing the whole request
@@ -922,10 +976,22 @@ func (s *Server) handlePrefixDetail() http.HandlerFunc {
 			return
 		}
 
-		// Combine prefix and length into CIDR notation
-		prefix := prefixParam + "/" + lenParam
+		// Look the prefix up in the text form net/netip prints, the form the
+		// tables store, so that any valid way of writing it finds the route.
+		parsed, err := netip.ParsePrefix(prefixParam + "/" + lenParam)
+		if err != nil {
+			http.Error(w, "Invalid prefix", http.StatusBadRequest)
 
-		routes, err := s.db.GetPrefixDetailsContext(r.Context(), prefix)
+			return
+		}
+		prefix := parsed.Masked().String()
+
+		routes, originASNs, err := s.db.GetPrefixDetailsContext(r.Context(), prefix)
+		if deadlinePassed(r.Context()) {
+			http.Error(w, requestTimeoutMessage, http.StatusGatewayTimeout)
+
+			return
+		}
 		if err != nil {
 			if errors.Is(err, database.ErrNoRoute) {
 				http.Error(w, "Prefix not found", http.StatusNotFound)
@@ -947,18 +1013,10 @@ func (s *Server) handlePrefixDetail() http.HandlerFunc {
 		originMap := make(map[int]*ASNInfo)
 		for _, route := range routes {
 			if _, exists := originMap[route.OriginASN]; !exists {
-				// Get AS info from database
-				asInfo, _, _ := s.db.GetASDetailsContext(r.Context(), route.OriginASN)
-				handle := ""
-				description := ""
-				if asInfo != nil {
-					handle = asInfo.Handle
-					description = asInfo.Description
-				}
 				originMap[route.OriginASN] = &ASNInfo{
 					ASN:         route.OriginASN,
-					Handle:      handle,
-					Description: description,
+					Handle:      originASNs[route.OriginASN].Handle,
+					Description: originASNs[route.OriginASN].Description,
 					PeerCount:   0,
 				}
 			}
@@ -1082,6 +1140,11 @@ func (s *Server) handlePrefixLength() http.HandlerFunc {
 		// Get random sample of prefixes
 		const maxPrefixes = 500
 		prefixes, err := s.db.GetRandomPrefixesByLengthContext(r.Context(), maskLength, ipVersion, maxPrefixes)
+		if deadlinePassed(r.Context()) {
+			http.Error(w, requestTimeoutMessage, http.StatusGatewayTimeout)
+
+			return
+		}
 		if err != nil {
 			s.logger.Error("Failed to get prefixes by length", "error", err)
 			http.Error(w, "Internal server error", http.StatusInternalServerError)
@@ -1173,6 +1236,11 @@ func (s *Server) handlePrefixLength6() http.HandlerFunc {
 		// Get random sample of prefixes
 		const maxPrefixes = 500
 		prefixes, err := s.db.GetRandomPrefixesByLengthContext(r.Context(), maskLength, ipVersion, maxPrefixes)
+		if deadlinePassed(r.Context()) {
+			http.Error(w, requestTimeoutMessage, http.StatusGatewayTimeout)
+
+			return
+		}
 		if err != nil {
 			s.logger.Error("Failed to get prefixes by length", "error", err)
 			http.Error(w, "Internal server error", http.StatusInternalServerError)

internal/server/handlers_test.go

@@ -0,0 +1,550 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"html"
+	"net/http"
+	"net/http/httptest"
+	"runtime"
+	"slices"
+	"strings"
+	"testing"
+	"time"
+
+	"git.eeqj.de/sneak/routewatch/internal/config"
+	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/logger"
+	"git.eeqj.de/sneak/routewatch/internal/metrics"
+	"git.eeqj.de/sneak/routewatch/internal/streamer"
+	"git.eeqj.de/sneak/routewatch/pkg/asinfo"
+	"github.com/google/uuid"
+)
+
+// blockingStatsDB embeds database.Store (left nil) and overrides only
+// GetStatsContext, which blocks until release is closed. The stats handlers
+// call it in a goroutine; every other Store method is unused on the timeout
+// path and would panic if called.
+type blockingStatsDB struct {
+	database.Store
+	release chan struct{}
+}
+
+func (d blockingStatsDB) GetStatsContext(_ context.Context) (database.Stats, error) {
+	<-d.release
+
+	return database.Stats{}, nil
+}
+
+// TestStatsHandlersDoNotLeakOnTimeout drives each stats handler repeatedly with
+// a request whose context times out before the database responds, then releases
+// the blocked queries and asserts the goroutine count returns to its starting
+// value. Before the fix the per-request goroutine sent on an unbuffered channel
+// that nothing received once the timeout won, so it blocked forever and every
+// poll leaked one goroutine.
+func TestStatsHandlersDoNotLeakOnTimeout(t *testing.T) {
+	release := make(chan struct{})
+	db := blockingStatsDB{release: release}
+	s := New(db, streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
+
+	handlers := map[string]http.HandlerFunc{
+		"status.json": s.handleStatusJSON(),
+		"stats":       s.handleStats(),
+	}
+
+	baseline := settledGoroutineCount()
+
+	const (
+		iterations     = 20
+		requestTimeout = 50 * time.Millisecond
+	)
+	for _, handler := range handlers {
+		for range iterations {
+			ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
+			req := httptest.NewRequest(http.MethodGet, "/", nil).WithContext(ctx)
+			handler(httptest.NewRecorder(), req)
+			cancel()
+		}
+	}
+
+	// Let the blocked queries finish; with buffered channels each goroutine's
+	// send now succeeds and the goroutine exits.
+	close(release)
+
+	if !waitForGoroutines(baseline) {
+		t.Fatalf("goroutines did not return to baseline %d, got %d",
+			baseline, runtime.NumGoroutine())
+	}
+}
+
+// TestStatsHandlersAnswerFromMemory checks that both stats handlers answer 200
+// with the live route counts and the prefix distribution while the database is
+// closed, so that any query would fail: the request path reads them from
+// memory. The prefix distribution query it used to run read every live route
+// and, on a large database, took the whole 4-second deadline, so
+// /api/v1/stats answered 500 (https://git.eeqj.de/sneak/routewatch/issues/30).
+// The oldest and newest route times still come from one-row lookups at the ends
+// of an index; with the database closed they are left out of the answer.
+func TestStatsHandlersAnswerFromMemory(t *testing.T) {
+	db, err := database.New(&config.Config{StateDir: t.TempDir()}, logger.New())
+	if err != nil {
+		t.Fatalf("database.New: %v", err)
+	}
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	if err := db.UpsertLiveRouteBatch([]*database.LiveRoute{
+		{
+			ID: uuid.New(), Prefix: "198.51.100.0/24", MaskLength: 24, IPVersion: 4,
+			OriginASN: 64500, PeerIP: "192.0.2.1", ASPath: []int{64500}, NextHop: "192.0.2.1",
+			LastUpdated: ts,
+		},
+		{
+			ID: uuid.New(), Prefix: "2001:db8::/32", MaskLength: 32, IPVersion: 6,
+			OriginASN: 64501, PeerIP: "2001:db8::1", ASPath: []int{64501}, NextHop: "2001:db8::1",
+			LastUpdated: ts,
+		},
+	}); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+	if err := db.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+
+	s := New(db, streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
+	handlers := map[string]http.HandlerFunc{
+		"status.json": s.handleStatusJSON(),
+		"stats":       s.handleStats(),
+	}
+
+	for name, handler := range handlers {
+		rec := httptest.NewRecorder()
+		handler(rec, httptest.NewRequest(http.MethodGet, "/", nil))
+		if rec.Code != http.StatusOK {
+			t.Errorf("%s: status %d, want %d; body %s", name, rec.Code, http.StatusOK, rec.Body)
+
+			continue
+		}
+
+		var body struct {
+			Data struct {
+				IPv4Routes             int                           `json:"ipv4_routes"`
+				IPv6Routes             int                           `json:"ipv6_routes"`
+				IPv4PrefixDistribution []database.PrefixDistribution `json:"ipv4_prefix_distribution"`
+				IPv6PrefixDistribution []database.PrefixDistribution `json:"ipv6_prefix_distribution"`
+			} `json:"data"`
+		}
+		if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
+			t.Fatalf("%s: decoding the answer: %v", name, err)
+		}
+
+		if body.Data.IPv4Routes != 1 || body.Data.IPv6Routes != 1 {
+			t.Errorf("%s: routes = (v4 %d, v6 %d), want (1, 1)", name, body.Data.IPv4Routes, body.Data.IPv6Routes)
+		}
+		wantV4 := []database.PrefixDistribution{{MaskLength: 24, Count: 1}}
+		if !slices.Equal(body.Data.IPv4PrefixDistribution, wantV4) {
+			t.Errorf("%s: IPv4 distribution = %v, want %v", name, body.Data.IPv4PrefixDistribution, wantV4)
+		}
+		wantV6 := []database.PrefixDistribution{{MaskLength: 32, Count: 1}}
+		if !slices.Equal(body.Data.IPv6PrefixDistribution, wantV6) {
+			t.Errorf("%s: IPv6 distribution = %v, want %v", name, body.Data.IPv6PrefixDistribution, wantV6)
+		}
+	}
+}
+
+// TestPrefixDetailHandlersParsePrefix checks that both prefix pages find a
+// stored route whatever valid text form the URL writes its prefix in, and
+// answer 400 for a prefix that does not parse. The tables store the form
+// net/netip prints. Before the fix the URL text was looked up as typed, so
+// "2001:DB8:0:0::/32" was not found although "2001:db8::/32" was stored, and
+// "foo/24" answered 500 (https://git.eeqj.de/sneak/routewatch/issues/71).
+func TestPrefixDetailHandlersParsePrefix(t *testing.T) {
+	db, err := database.New(&config.Config{StateDir: t.TempDir()}, logger.New())
+	if err != nil {
+		t.Fatalf("database.New: %v", err)
+	}
+	t.Cleanup(func() { _ = db.Close() })
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	if err := db.UpsertLiveRouteBatch([]*database.LiveRoute{
+		{
+			ID: uuid.New(), Prefix: "192.0.2.0/24", MaskLength: 24, IPVersion: 4,
+			OriginASN: 64500, PeerIP: "198.51.100.1", ASPath: []int{64500}, NextHop: "198.51.100.1",
+			LastUpdated: ts,
+		},
+		{
+			ID: uuid.New(), Prefix: "2001:db8::/32", MaskLength: 32, IPVersion: 6,
+			OriginASN: 64501, PeerIP: "2001:db8::1", ASPath: []int{64501}, NextHop: "2001:db8::1",
+			LastUpdated: ts,
+		},
+	}); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+
+	s := New(db, streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
+
+	tests := []struct {
+		path string
+		want int
+	}{
+		{"/api/v1/prefix/foo/24", http.StatusBadRequest},
+		{"/prefix/foo/24", http.StatusBadRequest},
+		{"/api/v1/prefix/2001:DB8:0:0::/32", http.StatusOK},
+		{"/prefix/2001:DB8:0:0::/32", http.StatusOK},
+		{"/api/v1/prefix/192.0.2.1/24", http.StatusOK},
+		{"/prefix/192.0.2.1/24", http.StatusOK},
+	}
+
+	for _, tt := range tests {
+		rec := httptest.NewRecorder()
+		s.router.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, tt.path, nil))
+		if rec.Code != tt.want {
+			t.Errorf("%s: status %d, want %d; body %s", tt.path, rec.Code, tt.want, rec.Body)
+		}
+	}
+}
+
+// failingASDetailsDB wraps a real store and fails every AS details lookup.
+type failingASDetailsDB struct {
+	database.Store
+}
+
+func (failingASDetailsDB) GetASDetailsContext(_ context.Context, _ int) (*database.ASN, []database.LiveRoute, error) {
+	return nil, nil, errors.New("AS details lookup failed")
+}
+
+// TestPrefixDetailShowsOriginNames checks that the prefix page shows each
+// origin AS's handle and description without looking up the AS's details,
+// which also read every route the AS originates. Before the fix the page did
+// that lookup once per origin, so with it failing the names were missing
+// (https://git.eeqj.de/sneak/routewatch/issues/67). The AS path column shows
+// handles too, so the test looks for the origin list's "(handle)" form.
+func TestPrefixDetailShowsOriginNames(t *testing.T) {
+	db, err := database.New(&config.Config{StateDir: t.TempDir()}, logger.New())
+	if err != nil {
+		t.Fatalf("database.New: %v", err)
+	}
+	t.Cleanup(func() { _ = db.Close() })
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	origins := []int{15169, 13335}
+	for _, asn := range origins {
+		if _, err := db.GetOrCreateASN(asn, ts); err != nil {
+			t.Fatalf("GetOrCreateASN(%d): %v", asn, err)
+		}
+	}
+	if err := db.UpsertLiveRouteBatch([]*database.LiveRoute{
+		{
+			ID: uuid.New(), Prefix: "192.0.2.0/24", MaskLength: 24, IPVersion: 4,
+			OriginASN: origins[0], PeerIP: "198.51.100.1", ASPath: []int{origins[0]}, NextHop: "198.51.100.1",
+			LastUpdated: ts,
+		},
+		{
+			ID: uuid.New(), Prefix: "192.0.2.0/24", MaskLength: 24, IPVersion: 4,
+			OriginASN: origins[1], PeerIP: "198.51.100.2", ASPath: []int{origins[1]}, NextHop: "198.51.100.2",
+			LastUpdated: ts,
+		},
+	}); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+
+	s := New(failingASDetailsDB{db}, streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
+	rec := httptest.NewRecorder()
+	s.router.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/prefix/192.0.2.0/24", nil))
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status %d, want %d; body %s", rec.Code, http.StatusOK, rec.Body)
+	}
+
+	page := rec.Body.String()
+	for _, asn := range origins {
+		info, ok := asinfo.Get(asn)
+		if !ok {
+			t.Fatalf("AS%d is not in the AS info data", asn)
+		}
+		if want := "(" + html.EscapeString(info.Handle) + ")"; !strings.Contains(page, want) {
+			t.Errorf("page does not show AS%d's handle %q", asn, want)
+		}
+		if want := html.EscapeString(info.Description); !strings.Contains(page, want) {
+			t.Errorf("page does not show AS%d's description %q", asn, want)
+		}
+	}
+}
+
+// shortRequestDeadline is the deadline the tests below give a request. The
+// server's 30-second limit and the stats handlers' 4-second limit inherit it,
+// so the tests do not wait for either.
+const shortRequestDeadline = 50 * time.Millisecond
+
+// TestRequestPastTimeLimitAnswers504 sends a request through the server's
+// router to a page and to a JSON route whose handlers wait for the time limit
+// to pass and return without answering. The page answers 504; the JSON route
+// answers 504 with the JSON error body. Before the fix both answered 408,
+// written by the time limit middleware from its own goroutine while the
+// handler could still be writing.
+func TestRequestPastTimeLimitAnswers504(t *testing.T) {
+	s := New(nil, streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
+
+	waitForTimeLimit := func(_ http.ResponseWriter, r *http.Request) {
+		<-r.Context().Done()
+	}
+	// Registered the way setupRoutes registers pages and JSON routes.
+	s.router.Get("/slow-page", waitForTimeLimit)
+	s.router.Get("/slow.json", JSONValidationMiddleware(http.HandlerFunc(waitForTimeLimit)).ServeHTTP)
+
+	tests := []struct {
+		path         string
+		wantJSONBody bool
+	}{
+		{path: "/slow-page"},
+		{path: "/slow.json", wantJSONBody: true},
+	}
+
+	for _, tt := range tests {
+		ctx, cancel := context.WithTimeout(context.Background(), shortRequestDeadline)
+		rec := httptest.NewRecorder()
+		s.router.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, tt.path, nil).WithContext(ctx))
+		cancel()
+
+		if rec.Code != http.StatusGatewayTimeout {
+			t.Errorf("%s: status %d, want %d; body %s", tt.path, rec.Code, http.StatusGatewayTimeout, rec.Body)
+		}
+		if tt.wantJSONBody {
+			checkJSONErrorCode(t, tt.path, rec, http.StatusGatewayTimeout)
+		}
+	}
+}
+
+// TestStatsHandlersAnswer504WhenDatabaseReadRunsOut calls each stats handler
+// with a store that does not answer before the handler's 4-second limit runs
+// out, and checks that the handler itself answers 504 with the JSON error
+// body. Before the fix status.json answered 408, and /api/v1/stats wrote
+// nothing, which the JSON check on its route turned into 500.
+func TestStatsHandlersAnswer504WhenDatabaseReadRunsOut(t *testing.T) {
+	release := make(chan struct{})
+	defer close(release)
+	db := blockingStatsDB{release: release}
+	s := New(db, streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
+
+	handlers := map[string]http.HandlerFunc{
+		"status.json": s.handleStatusJSON(),
+		"stats":       s.handleStats(),
+	}
+
+	for name, handler := range handlers {
+		ctx, cancel := context.WithTimeout(context.Background(), shortRequestDeadline)
+		rec := httptest.NewRecorder()
+		handler(rec, httptest.NewRequest(http.MethodGet, "/", nil).WithContext(ctx))
+		cancel()
+
+		if rec.Code != http.StatusGatewayTimeout {
+			t.Errorf("%s: status %d, want %d; body %s", name, rec.Code, http.StatusGatewayTimeout, rec.Body)
+		}
+		checkJSONErrorCode(t, name, rec, http.StatusGatewayTimeout)
+	}
+}
+
+// slowDB embeds database.Store (left nil) and overrides the reads the routes
+// in TestRoutesAnswer504WhenDatabaseReadIsCutOff make. Each read waits until
+// its context ends and then answers as the real store does when the time
+// limit cuts it off: the IP read with the context's error, the prefix read
+// that there is no route, and the others with what they had read, here
+// nothing, and no error. Every other Store method is unused and would panic
+// if called.
+type slowDB struct {
+	database.Store
+}
+
+func (slowDB) GetStatsContext(ctx context.Context) (database.Stats, error) {
+	<-ctx.Done()
+
+	return database.Stats{}, nil
+}
+
+func (slowDB) GetIPInfoContext(ctx context.Context, _ string) (*database.IPInfo, error) {
+	<-ctx.Done()
+
+	return nil, ctx.Err()
+}
+
+func (slowDB) GetASDetailsContext(ctx context.Context, asn int) (*database.ASN, []database.LiveRoute, error) {
+	<-ctx.Done()
+
+	return &database.ASN{ASN: asn}, nil, nil
+}
+
+func (slowDB) GetPrefixDetailsContext(ctx context.Context, _ string) ([]database.LiveRoute, map[int]database.ASN, error) {
+	<-ctx.Done()
+
+	return nil, nil, database.ErrNoRoute
+}
+
+func (slowDB) GetRandomPrefixesByLengthContext(ctx context.Context, _, _, _ int) ([]database.LiveRoute, error) {
+	<-ctx.Done()
+
+	return nil, nil
+}
+
+// TestRoutesAnswer504WhenDatabaseReadIsCutOff sends a request through the
+// server's router for each route that reads the database, with a store whose
+// reads are cut off when the request's time limit passes. Each route answers
+// 504 with the time limit message. Without its check after the read, a route
+// answers with what the cut-off read returned: 500, 404, 200, or, on a page
+// that stops before rendering once the request has ended, 504 with an empty
+// body. The health check is left out: it answers 503 when its own 2-second
+// ping runs out.
+func TestRoutesAnswer504WhenDatabaseReadIsCutOff(t *testing.T) {
+	s := New(slowDB{}, streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
+
+	tests := []struct {
+		path         string
+		wantJSONBody bool
+	}{
+		{path: "/as/64500"},
+		{path: "/prefix/192.0.2.0/24"},
+		{path: "/prefixlength/24"},
+		{path: "/prefixlength6/48"},
+		{path: "/status.json", wantJSONBody: true},
+		{path: "/ip/192.0.2.1", wantJSONBody: true},
+		{path: "/api/v1/stats", wantJSONBody: true},
+		{path: "/api/v1/ip/192.0.2.1", wantJSONBody: true},
+		{path: "/api/v1/as/64500", wantJSONBody: true},
+		{path: "/api/v1/prefix/192.0.2.0/24", wantJSONBody: true},
+	}
+
+	for _, tt := range tests {
+		checkRouteAnswers504(t, s, tt.path, tt.wantJSONBody)
+	}
+}
+
+// slowSecondReadDB embeds database.Store (left nil) and overrides the reads
+// of the routes that read the database twice. The first read answers at once;
+// the second, the AS page's peers read or the stats routes' WHOIS read, waits
+// until its context ends and then answers with the context's error, as the
+// real store does.
+type slowSecondReadDB struct {
+	database.Store
+}
+
+func (slowSecondReadDB) GetASDetailsContext(_ context.Context, asn int) (*database.ASN, []database.LiveRoute, error) {
+	return &database.ASN{ASN: asn}, nil, nil
+}
+
+func (slowSecondReadDB) GetASPeersContext(ctx context.Context, _ int) ([]database.ASPeer, error) {
+	<-ctx.Done()
+
+	return nil, ctx.Err()
+}
+
+func (slowSecondReadDB) GetStatsContext(_ context.Context) (database.Stats, error) {
+	return database.Stats{}, nil
+}
+
+func (slowSecondReadDB) GetWHOISStats(ctx context.Context, _ time.Duration) (*database.WHOISStats, error) {
+	<-ctx.Done()
+
+	return nil, ctx.Err()
+}
+
+// idleASNFetcher is a WHOIS fetcher that does nothing. The stats handlers
+// read the WHOIS stats only when the server has a fetcher.
+type idleASNFetcher struct{}
+
+func (idleASNFetcher) QueueImmediate(int) {}
+
+func (idleASNFetcher) GetStats() ASNFetcherStats {
+	return ASNFetcherStats{}
+}
+
+// TestRoutesAnswer504WhenSecondDatabaseReadIsCutOff sends a request through
+// the server's router for each route that reads the database twice, with a
+// store that answers the first read and cuts off the second when the
+// request's time limit passes. Each route answers 504 with the time limit
+// message. Without the check after the second read, the AS page answers 504
+// with an empty body and the stats routes answer 200 without the WHOIS stats.
+func TestRoutesAnswer504WhenSecondDatabaseReadIsCutOff(t *testing.T) {
+	s := New(slowSecondReadDB{}, streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
+	s.SetASNFetcher(idleASNFetcher{})
+
+	tests := []struct {
+		path         string
+		wantJSONBody bool
+	}{
+		{path: "/as/64500"},
+		{path: "/status.json", wantJSONBody: true},
+		{path: "/api/v1/stats", wantJSONBody: true},
+	}
+
+	for _, tt := range tests {
+		checkRouteAnswers504(t, s, tt.path, tt.wantJSONBody)
+	}
+}
+
+// checkRouteAnswers504 sends a request for path through the server's router
+// with a short deadline and checks that it answers 504 with the time limit
+// message: the JSON error body on JSON routes, the plain message on pages.
+func checkRouteAnswers504(t *testing.T, s *Server, path string, wantJSONBody bool) {
+	t.Helper()
+
+	ctx, cancel := context.WithTimeout(context.Background(), shortRequestDeadline)
+	defer cancel()
+	rec := httptest.NewRecorder()
+	s.router.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, path, nil).WithContext(ctx))
+
+	if rec.Code != http.StatusGatewayTimeout {
+		t.Errorf("%s: status %d, want %d; body %s", path, rec.Code, http.StatusGatewayTimeout, rec.Body)
+	}
+	if wantJSONBody {
+		checkJSONErrorCode(t, path, rec, http.StatusGatewayTimeout)
+	} else if body := strings.TrimSpace(rec.Body.String()); body != requestTimeoutMessage {
+		t.Errorf("%s: body %q, want %q", path, body, requestTimeoutMessage)
+	}
+}
+
+// checkJSONErrorCode checks that rec holds the JSON error body with the given
+// code.
+func checkJSONErrorCode(t *testing.T, name string, rec *httptest.ResponseRecorder, want int) {
+	t.Helper()
+
+	var body struct {
+		Status string `json:"status"`
+		Error  struct {
+			Code int `json:"code"`
+		} `json:"error"`
+	}
+	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
+		t.Errorf("%s: decoding the answer %q: %v", name, rec.Body, err)
+
+		return
+	}
+	if body.Status != "error" || body.Error.Code != want {
+		t.Errorf("%s: answer %s, want status \"error\" and error code %d", name, rec.Body, want)
+	}
+}
+
+// settledGoroutineCount lets transient goroutines finish, then reports the
+// current count.
+func settledGoroutineCount() int {
+	prev := runtime.NumGoroutine()
+	for range 20 {
+		time.Sleep(10 * time.Millisecond)
+		cur := runtime.NumGoroutine()
+		if cur == prev {
+			return cur
+		}
+		prev = cur
+	}
+
+	return prev
+}
+
+// waitForGoroutines waits until the goroutine count drops to target or below.
+func waitForGoroutines(target int) bool {
+	for range 100 {
+		if runtime.NumGoroutine() <= target {
+			return true
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+
+	return false
+}

internal/server/middleware.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"log/slog"
 	"net/http"
@@ -109,142 +110,28 @@ func JSONResponseMiddleware(next http.Handler) http.Handler {
 	})
 }
 
-// timeoutWriter wraps ResponseWriter to prevent concurrent writes after timeout
-type timeoutWriter struct {
-	http.ResponseWriter
-	mu      sync.Mutex
-	written bool
-	header  http.Header // cached header to prevent concurrent access
-}
+// requestTimeoutMessage is the error message sent with 504 Gateway Timeout.
+const requestTimeoutMessage = "Request timeout"
 
-func (tw *timeoutWriter) Write(b []byte) (int, error) {
-	tw.mu.Lock()
-	defer tw.mu.Unlock()
-
-	if tw.written {
-		return 0, nil // Discard writes after timeout
-	}
-
-	return tw.ResponseWriter.Write(b)
-}
-
-func (tw *timeoutWriter) WriteHeader(statusCode int) {
-	tw.mu.Lock()
-	defer tw.mu.Unlock()
-
-	if tw.written {
-		return // Discard writes after timeout
-	}
-
-	tw.ResponseWriter.WriteHeader(statusCode)
-}
-
-func (tw *timeoutWriter) Header() http.Header {
-	tw.mu.Lock()
-	defer tw.mu.Unlock()
-
-	if tw.written {
-		// Return a copy to prevent modifications after timeout
-		if tw.header == nil {
-			tw.header = make(http.Header)
-		}
-
-		return tw.header
-	}
-
-	return tw.ResponseWriter.Header()
-}
-
-func (tw *timeoutWriter) markWritten() {
-	tw.mu.Lock()
-	defer tw.mu.Unlock()
-	tw.written = true
-}
-
-// TimeoutMiddleware creates an HTTP middleware that enforces a request timeout.
-// If the handler does not complete within the specified duration, the middleware
-// returns a JSON error response with HTTP status 408 (Request Timeout).
+// deadlinePassed reports whether ctx ended because its deadline passed.
 //
-// The timeout parameter specifies the maximum duration allowed for request processing.
-// The returned middleware handles panics from the wrapped handler by re-panicking
-// after cleanup, and prevents concurrent writes to the response after timeout occurs.
-func TimeoutMiddleware(timeout time.Duration, logger *slog.Logger) func(http.Handler) http.Handler {
-	return func(next http.Handler) http.Handler {
-		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			startTime := time.Now()
-
-			ctx, cancel := context.WithTimeout(r.Context(), timeout)
-			defer cancel()
-
-			tw := &timeoutWriter{
-				ResponseWriter: w,
-				header:         make(http.Header),
-			}
-
-			done := make(chan struct{})
-			panicChan := make(chan interface{}, 1)
-
-			go func() {
-				defer func() {
-					if p := recover(); p != nil {
-						panicChan <- p
-					}
-				}()
-
-				next.ServeHTTP(tw, r.WithContext(ctx))
-				close(done)
-			}()
-
-			select {
-			case p := <-panicChan:
-				panic(p)
-			case <-done:
-				return
-			case <-ctx.Done():
-				tw.markWritten() // Prevent the handler from writing after timeout
-				execTime := time.Since(startTime)
-
-				// Log the timeout as a warning
-				logger.Warn("Request timeout",
-					"method", r.Method,
-					"path", r.URL.Path,
-					"duration_ms", execTime.Milliseconds(),
-					"remote_addr", r.RemoteAddr,
-				)
-
-				// Write directly to the underlying writer since we've marked tw as written
-				// This is safe because markWritten() prevents the handler from writing
-				tw.mu.Lock()
-				w.Header().Set("Content-Type", "application/json")
-				w.WriteHeader(http.StatusRequestTimeout)
-				tw.mu.Unlock()
-
-				response := map[string]interface{}{
-					"status": "error",
-					"error": map[string]interface{}{
-						"msg":  "Request timeout",
-						"code": http.StatusRequestTimeout,
-					},
-					"@meta": map[string]interface{}{
-						"time_zone":      "UTC",
-						"api_version":    1,
-						"execution_time": fmt.Sprintf("%d ms", execTime.Milliseconds()),
-					},
-				}
-
-				_ = json.NewEncoder(w).Encode(response)
-			}
-		})
-	}
+// A handler calls it right after each database read or host name lookup,
+// before it looks at what came back, error or not, and answers 504 if it
+// reports true. A read cut off by the time limit can return an error, or part
+// of its rows or none of them without one, so only this check tells a cut-off
+// read from a complete one.
+func deadlinePassed(ctx context.Context) bool {
+	return errors.Is(ctx.Err(), context.DeadlineExceeded)
 }
 
 // JSONValidationMiddleware is an HTTP middleware that validates JSON API responses.
 // It ensures that responses with Content-Type "application/json" contain valid JSON.
 //
 // If a response is not valid JSON or is empty when JSON is expected, the middleware
-// returns a properly formatted JSON error response. For timeout errors (status 408),
-// the error message will be "Request timeout". For other errors, it returns
-// "Internal server error" with status 500 if the original status was 200.
+// returns a properly formatted JSON error response. If the request's time limit
+// has passed, it answers 504 with the error message "Request timeout". For other
+// errors, it returns "Internal server error" with status 500 if the original
+// status was 200.
 //
 // Non-JSON responses are passed through unchanged.
 func JSONValidationMiddleware(next http.Handler) http.Handler {
@@ -293,11 +180,14 @@ func JSONValidationMiddleware(next http.Handler) http.Handler {
 		if statusCode == http.StatusOK {
 			statusCode = http.StatusInternalServerError
 		}
+		if deadlinePassed(r.Context()) {
+			statusCode = http.StatusGatewayTimeout
+		}
 		w.WriteHeader(statusCode)
 
 		errorMsg := "Internal server error"
-		if statusCode == http.StatusRequestTimeout {
-			errorMsg = "Request timeout"
+		if statusCode == http.StatusGatewayTimeout {
+			errorMsg = requestTimeoutMessage
 		}
 
 		response := map[string]interface{}{

internal/server/routes.go

@@ -16,9 +16,12 @@ func (s *Server) setupRoutes() {
 	r.Use(middleware.RealIP)
 	r.Use(RequestLoggerMiddleware(s.logger.Logger)) // Structured request logging
 	r.Use(middleware.Recoverer)
-	const requestTimeout = 30 * time.Second // Increased from 8s for slow queries
-	r.Use(TimeoutMiddleware(requestTimeout, s.logger.Logger))
 	r.Use(JSONResponseMiddleware)
+	// Timeout must come after JSONResponseMiddleware, which sends its answer
+	// when the handler returns and would send a 200 ahead of Timeout's 504 for
+	// a handler that wrote nothing.
+	const requestTimeout = 30 * time.Second // Increased from 8s for slow queries
+	r.Use(middleware.Timeout(requestTimeout))
 
 	// Routes
 	r.Get("/", s.handleIndex())

internal/server/server.go

@@ -3,10 +3,13 @@ package server
 
 import (
 	"context"
+	"fmt"
+	"net"
 	"net/http"
-	"os"
+	"strconv"
 	"time"
 
+	"git.eeqj.de/sneak/routewatch/internal/config"
 	"git.eeqj.de/sneak/routewatch/internal/database"
 	"git.eeqj.de/sneak/routewatch/internal/logger"
 	"git.eeqj.de/sneak/routewatch/internal/streamer"
@@ -33,16 +36,18 @@ type Server struct {
 	db         database.Store
 	streamer   *streamer.Streamer
 	logger     *logger.Logger
+	port       int
 	srv        *http.Server
 	asnFetcher ASNFetcher
 }
 
 // New creates a new HTTP server
-func New(db database.Store, streamer *streamer.Streamer, logger *logger.Logger) *Server {
+func New(db database.Store, streamer *streamer.Streamer, logger *logger.Logger, cfg *config.Config) *Server {
 	s := &Server{
 		db:       db,
 		streamer: streamer,
 		logger:   logger,
+		port:     cfg.Port,
 	}
 
 	s.setupRoutes()
@@ -50,14 +55,12 @@ func New(db database.Store, streamer *streamer.Streamer, logger *logger.Logger)
 	return s
 }
 
-// Start starts the HTTP server
+// Start listens on the configured port and serves HTTP in the background.
+// It returns an error if it cannot listen, for example because the port is
+// already in use.
 func (s *Server) Start() error {
-	port := os.Getenv("PORT")
-	if port == "" {
-		port = "8080"
-	}
-
 	const (
+		network           = "tcp"
 		readHeaderTimeout = 40 * time.Second
 		readTimeout       = 60 * time.Second
 		writeTimeout      = 60 * time.Second
@@ -65,7 +68,7 @@ func (s *Server) Start() error {
 	)
 
 	s.srv = &http.Server{
-		Addr:              ":" + port,
+		Addr:              ":" + strconv.Itoa(s.port),
 		Handler:           s.router,
 		ReadHeaderTimeout: readHeaderTimeout,
 		ReadTimeout:       readTimeout,
@@ -73,12 +76,17 @@ func (s *Server) Start() error {
 		IdleTimeout:       idleTimeout,
 	}
 
-	s.logger.Info("Starting HTTP server", "port", port, "addr", s.srv.Addr)
+	s.logger.Info("Starting HTTP server", "port", s.port, "addr", s.srv.Addr)
+
+	listener, err := net.Listen(network, s.srv.Addr)
+	if err != nil {
+		return fmt.Errorf("starting HTTP server: %w", err)
+	}
+
+	s.logger.Info("HTTP server listening", "addr", listener.Addr().String())
 
-	// Start in goroutine but log when actually listening
 	go func() {
-		s.logger.Info("HTTP server listening", "addr", s.srv.Addr)
-		if err := s.srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+		if err := s.srv.Serve(listener); err != nil && err != http.ErrServerClosed {
 			s.logger.Error("HTTP server error", "error", err)
 		}
 	}()

internal/server/server_test.go

@@ -0,0 +1,33 @@
+package server
+
+import (
+	"context"
+	"net"
+	"testing"
+
+	"git.eeqj.de/sneak/routewatch/internal/config"
+	"git.eeqj.de/sneak/routewatch/internal/logger"
+	"git.eeqj.de/sneak/routewatch/internal/metrics"
+	"git.eeqj.de/sneak/routewatch/internal/streamer"
+)
+
+// TestStartFailsWhenPortIsHeld holds a port with a listener of its own and
+// checks that Start on that port returns an error. Before the fix Start
+// listened in a goroutine, only logged the failure and returned nil, so the
+// daemon kept running without its web server.
+func TestStartFailsWhenPortIsHeld(t *testing.T) {
+	held, err := net.Listen("tcp", ":0")
+	if err != nil {
+		t.Fatalf("failed to open the test listener: %v", err)
+	}
+	defer func() { _ = held.Close() }()
+
+	port := held.Addr().(*net.TCPAddr).Port
+	log := logger.New()
+	s := New(nil, streamer.New(log, metrics.New()), log, &config.Config{Port: port})
+	defer func() { _ = s.Stop(context.Background()) }()
+
+	if err := s.Start(); err == nil {
+		t.Fatalf("Start returned nil while port %d was held by another listener", port)
+	}
+}

internal/streamer/streamer.go

@@ -7,6 +7,7 @@ import (
 	"compress/gzip"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"math"
@@ -48,6 +49,7 @@ const (
 	metricsUpdateRate     = time.Second
 	minBackoffDelay       = 5 * time.Second
 	maxBackoffDelay       = 320 * time.Second
+	streamIdleTimeout     = 60 * time.Second // Reconnect when no line arrives for this long
 	metricsLogInterval    = 10 * time.Second
 	bytesPerKB            = 1024
 	bytesPerMB            = 1024 * 1024
@@ -58,6 +60,9 @@ const (
 	backpressureSlope     = 2.0 // Slope for linear drop probability increase
 )
 
+// errStreamEnded is returned by stream when RIS Live ends the response.
+var errStreamEnded = errors.New("RIS Live ended the stream")
+
 // MessageHandler defines the interface for processing RIS messages.
 // Implementations must specify which message types they want to receive,
 // how to process messages, and their desired queue capacity.
@@ -73,7 +78,7 @@ type MessageHandler interface {
 	// QueueCapacity returns the desired queue capacity for this handler.
 	// Handlers that process quickly can have larger queues to buffer bursts.
 	// When the queue fills up, messages will be dropped according to the
-	// backpressure algorithm.
+	// backpressure algorithm, except STATE messages, which wait for room.
 	QueueCapacity() int
 }
 
@@ -106,6 +111,9 @@ type handlerInfo struct {
 type Streamer struct {
 	logger       *logger.Logger
 	client       *http.Client
+	url          string
+	idleTimeout  time.Duration // Drop the connection when no line arrives for this long
+	minBackoff   time.Duration // First wait before reconnecting; doubles up to maxBackoffDelay
 	handlers     []*handlerInfo
 	rawHandler   RawMessageHandler
 	mu           sync.RWMutex
@@ -123,7 +131,10 @@ type Streamer struct {
 // The metrics tracker is used to record message counts, bytes received, and connection status.
 func New(logger *logger.Logger, metrics *metrics.Tracker) *Streamer {
 	return &Streamer{
-		logger: logger,
+		logger:      logger,
+		url:         risLiveURL,
+		idleTimeout: streamIdleTimeout,
+		minBackoff:  minBackoffDelay,
 		client: &http.Client{
 			Timeout: 0, // No timeout for streaming
 			Transport: &http.Transport{
@@ -208,9 +219,14 @@ func (s *Streamer) Start() error {
 // the connection status in metrics. This method is safe to call multiple times.
 func (s *Streamer) Stop() {
 	s.mu.Lock()
-	if s.cancel != nil {
-		s.cancel()
+	if s.cancel == nil {
+		// Not started, or already stopped: closing the queues again would panic.
+		s.mu.Unlock()
+
+		return
 	}
+	s.cancel()
+	s.cancel = nil
 	// Close all handler queues to signal workers to stop
 	for _, info := range s.handlers {
 		close(info.queue)
@@ -398,7 +414,7 @@ func (s *Streamer) updateMetrics(messageBytes int) {
 
 // streamWithReconnect handles streaming with automatic reconnection and exponential backoff
 func (s *Streamer) streamWithReconnect(ctx context.Context) {
-	backoffDelay := minBackoffDelay
+	backoffDelay := s.minBackoff
 	consecutiveFailures := 0
 
 	for {
@@ -415,8 +431,9 @@ func (s *Streamer) streamWithReconnect(ctx context.Context) {
 		err := s.stream(ctx)
 		streamDuration := time.Since(startTime)
 
-		if err == nil {
-			// Clean exit (context cancelled)
+		// Only Stop ends the streamer. A stream that ends any other way,
+		// with or without an error, is a disconnect and is reconnected.
+		if ctx.Err() != nil {
 			return
 		}
 
@@ -427,17 +444,13 @@ func (s *Streamer) streamWithReconnect(ctx context.Context) {
 			"stream_duration", streamDuration)
 		s.metrics.SetConnected(false)
 
-		// Check if context is cancelled
-		if ctx.Err() != nil {
-			return
-		}
-
-		// If we streamed for more than 30 seconds, reset the backoff
-		// This indicates we had a successful connection that received data
+		// A stream that lasted more than 30 seconds resets the backoff. That
+		// includes a stream dropped after streamIdleTimeout with no line, so
+		// a silent feed is retried after the first backoff delay every time.
 		if streamDuration > 30*time.Second {
 			s.logger.Info("Resetting backoff delay due to successful connection",
 				"stream_duration", streamDuration)
-			backoffDelay = minBackoffDelay
+			backoffDelay = s.minBackoff
 			consecutiveFailures = 0
 		} else {
 			// Increment consecutive failures
@@ -463,7 +476,20 @@ func (s *Streamer) streamWithReconnect(ctx context.Context) {
 }
 
 func (s *Streamer) stream(ctx context.Context) error {
-	req, err := http.NewRequestWithContext(ctx, "GET", risLiveURL, nil)
+	// connCtx is scoped to this single connection: cancelling it when stream
+	// returns stops the ticker goroutines below, so a reconnect does not leak
+	// them. Without this they would live until the streamer's lifetime context
+	// is cancelled, leaking two per reconnect.
+	connCtx, connCancel := context.WithCancel(ctx)
+	defer connCancel()
+
+	// The idle timer drops the connection, by cancelling connCtx, when no
+	// line arrives for s.idleTimeout. Each line read starts it over. It
+	// also covers the wait for the server to answer.
+	idleTimer := time.AfterFunc(s.idleTimeout, connCancel)
+	defer idleTimer.Stop()
+
+	req, err := http.NewRequestWithContext(connCtx, "GET", s.url, nil)
 	if err != nil {
 		return fmt.Errorf("failed to create request: %w", err)
 	}
@@ -516,7 +542,7 @@ func (s *Streamer) stream(ctx context.Context) error {
 			select {
 			case <-metricsTicker.C:
 				s.logMetrics()
-			case <-ctx.Done():
+			case <-connCtx.Done():
 				return
 			}
 		}
@@ -536,7 +562,7 @@ func (s *Streamer) stream(ctx context.Context) error {
 					s.metrics.RecordWireBytes(delta)
 					lastWireBytes = currentBytes
 				}
-			case <-ctx.Done():
+			case <-connCtx.Done():
 				return
 			}
 		}
@@ -545,6 +571,8 @@ func (s *Streamer) stream(ctx context.Context) error {
 	scanner := bufio.NewScanner(reader)
 
 	for scanner.Scan() {
+		idleTimer.Reset(s.idleTimeout)
+
 		select {
 		case <-ctx.Done():
 			s.logger.Info("Stream stopped by context")
@@ -601,7 +629,7 @@ func (s *Streamer) stream(ctx context.Context) error {
 
 		// Process based on message type
 		switch msg.Type {
-		case "UPDATE":
+		case ristypes.MessageTypeUpdate:
 			// Process BGP UPDATE messages
 			// Will be dispatched to handlers
 		case "RIS_PEER_STATE":
@@ -640,9 +668,9 @@ func (s *Streamer) stream(ctx context.Context) error {
 			)
 
 			continue
-		case "STATE":
-			// Peer state changes - silently ignore
-			continue
+		case ristypes.MessageTypeState:
+			// The BGP session with the peer changed state, for example went
+			// down. Dispatched to the handlers that want it.
 		default:
 			s.logger.Warn("Unknown message type, skipping",
 				"type", msg.Type,
@@ -651,46 +679,79 @@ func (s *Streamer) stream(ctx context.Context) error {
 			continue
 		}
 
-		// Dispatch to interested handlers
+		// Dispatch to interested handlers. Stop cancels ctx and closes the
+		// queues under the write lock, so if ctx is cancelled here, under the
+		// read lock, the queues are closed and must not be sent to.
 		s.mu.RLock()
+		if ctx.Err() != nil {
+			s.mu.RUnlock()
+
+			return ctx.Err()
+		}
 		for _, info := range s.handlers {
 			if !info.handler.WantsMessage(msg.Type) {
 				continue
 			}
 
-			// Check if we should drop due to backpressure
-			if s.shouldDropForBackpressure(info) {
+			if !s.queueMessage(connCtx, info, &msg) {
 				atomic.AddUint64(&info.metrics.droppedCount, 1)
 				atomic.AddUint64(&s.totalDropped, 1)
 
 				continue
 			}
 
-			// Try to queue the message
-			select {
-			case info.queue <- &msg:
-				// Message queued successfully
-				// Update high water mark if needed
-				queueLen := len(info.queue)
-				info.metrics.mu.Lock()
-				if queueLen > info.metrics.queueHighWaterMark {
-					info.metrics.queueHighWaterMark = queueLen
-				}
-				info.metrics.mu.Unlock()
-			default:
-				// Queue is full, drop the message
-				atomic.AddUint64(&info.metrics.droppedCount, 1)
-				atomic.AddUint64(&s.totalDropped, 1)
+			// Update high water mark if needed
+			queueLen := len(info.queue)
+			info.metrics.mu.Lock()
+			if queueLen > info.metrics.queueHighWaterMark {
+				info.metrics.queueHighWaterMark = queueLen
 			}
+			info.metrics.mu.Unlock()
 		}
 		s.mu.RUnlock()
 	}
 
+	if ctx.Err() != nil {
+		return ctx.Err()
+	}
+
+	if connCtx.Err() != nil {
+		return fmt.Errorf("no line received for %s", s.idleTimeout)
+	}
+
 	if err := scanner.Err(); err != nil {
 		return fmt.Errorf("scanner error: %w", err)
 	}
 
-	return nil
+	return errStreamEnded
+}
+
+// queueMessage puts msg on the handler's queue and reports whether it did. A
+// message is dropped while the queue is filling up (shouldDropForBackpressure)
+// or full, except a STATE message: one whose state is down is the only notice
+// that all of a peer's routes are gone, so a STATE message waits for room
+// instead. The wait ends if the idle timer drops the connection by cancelling
+// connCtx, so the read loop never waits longer than its idle timeout.
+func (s *Streamer) queueMessage(connCtx context.Context, info *handlerInfo, msg *ristypes.RISMessage) bool {
+	if msg.Type == ristypes.MessageTypeState {
+		select {
+		case info.queue <- msg:
+			return true
+		case <-connCtx.Done():
+			return false
+		}
+	}
+
+	if s.shouldDropForBackpressure(info) {
+		return false
+	}
+
+	select {
+	case info.queue <- msg:
+		return true
+	default:
+		return false
+	}
 }
 
 // shouldDropForBackpressure determines if a message should be dropped based on queue utilization

internal/streamer/streamer_test.go

@@ -1,10 +1,19 @@
 package streamer
 
 import (
+	"context"
+	"errors"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"runtime"
+	"sync/atomic"
 	"testing"
+	"time"
 
 	"git.eeqj.de/sneak/routewatch/internal/logger"
 	"git.eeqj.de/sneak/routewatch/internal/metrics"
+	"git.eeqj.de/sneak/routewatch/internal/ristypes"
 )
 
 func TestNewStreamer(t *testing.T) {
@@ -31,4 +40,376 @@ func TestNewStreamer(t *testing.T) {
 	if s.metrics != metricsTracker {
 		t.Error("metrics tracker not set correctly")
 	}
+
+	if s.idleTimeout != streamIdleTimeout {
+		t.Errorf("idleTimeout = %s, want %s", s.idleTimeout, streamIdleTimeout)
+	}
+
+	if s.minBackoff != minBackoffDelay {
+		t.Errorf("minBackoff = %s, want %s", s.minBackoff, minBackoffDelay)
+	}
+}
+
+// TestStreamDoesNotLeakTickersAcrossReconnects drives many short-lived
+// connections (each stream call is one reconnect cycle) and asserts the
+// goroutine count returns to its starting value. Each connection starts two
+// ticker goroutines; before the fix they lived until the streamer's lifetime
+// context was cancelled, so every reconnect leaked two.
+func TestStreamDoesNotLeakTickersAcrossReconnects(t *testing.T) {
+	// The handler returns immediately, so the response body is empty and each
+	// stream call ends at once, standing in for a dropped connection.
+	srv := httptest.NewServer(http.HandlerFunc(func(_ http.ResponseWriter, _ *http.Request) {}))
+	defer srv.Close()
+
+	s := New(logger.New(), metrics.New())
+	s.url = srv.URL
+
+	// One warm-up connection so any persistent HTTP transport goroutine exists
+	// before we take the baseline.
+	if err := s.stream(context.Background()); !errors.Is(err, errStreamEnded) {
+		t.Fatalf("warm-up stream returned %v, want %v", err, errStreamEnded)
+	}
+	s.client.CloseIdleConnections()
+
+	baseline := settledGoroutineCount()
+
+	const reconnects = 20
+	for range reconnects {
+		if err := s.stream(context.Background()); !errors.Is(err, errStreamEnded) {
+			t.Fatalf("stream returned %v, want %v", err, errStreamEnded)
+		}
+	}
+	s.client.CloseIdleConnections()
+
+	if !waitForGoroutines(baseline) {
+		t.Fatalf("goroutines did not return to baseline %d after %d reconnects, got %d",
+			baseline, reconnects, runtime.NumGoroutine())
+	}
+}
+
+// updateLine is one UPDATE message as RIS Live sends it.
+const updateLine = `{"type":"ris_message","data":{"type":"UPDATE","peer":"192.0.2.1",` +
+	`"peer_asn":"64496","timestamp":1700000000}}` + "\n"
+
+// updateHandler wants UPDATE messages. For each one it handles it sends on
+// handled if there is room, and otherwise does nothing; a nil handled is
+// never sent on.
+type updateHandler struct {
+	handled chan struct{}
+}
+
+func (updateHandler) WantsMessage(messageType string) bool { return messageType == "UPDATE" }
+func (updateHandler) QueueCapacity() int                   { return 10 }
+
+func (h updateHandler) HandleMessage(*ristypes.RISMessage) {
+	select {
+	case h.handled <- struct{}{}:
+	default:
+	}
+}
+
+// stateDownLine is the STATE message RIS Live sends when the collector's BGP
+// session with the peer stateDownPeer goes down.
+const (
+	stateDownPeer = "192.0.2.1"
+	stateDownLine = `{"type":"ris_message","data":{"type":"STATE","peer":"` + stateDownPeer + `",` +
+		`"peer_asn":"64496","timestamp":1700000000,"state":"down"}}` + "\n"
+)
+
+// stateHandler wants STATE messages only. Tests read what it is handed from
+// its queue, so HandleMessage does nothing.
+type stateHandler struct{}
+
+func (stateHandler) WantsMessage(messageType string) bool {
+	return messageType == ristypes.MessageTypeState
+}
+func (stateHandler) QueueCapacity() int                 { return 10 }
+func (stateHandler) HandleMessage(*ristypes.RISMessage) {}
+
+// TestStreamHandsStateMessagesToHandlersThatWantThem has the server send one
+// STATE message whose state is down. The streamer must queue it, with its
+// peer and state, for a handler that wants STATE messages.
+func TestStreamHandsStateMessagesToHandlersThatWantThem(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		_, _ = io.WriteString(w, stateDownLine)
+	}))
+	defer srv.Close()
+
+	s := New(logger.New(), metrics.New())
+	s.url = srv.URL
+	s.RegisterHandler(stateHandler{})
+
+	if err := s.stream(context.Background()); !errors.Is(err, errStreamEnded) {
+		t.Fatalf("stream returned %v, want %v", err, errStreamEnded)
+	}
+
+	select {
+	case msg := <-s.handlers[0].queue:
+		if msg.Type != ristypes.MessageTypeState || msg.Peer != stateDownPeer || msg.State != ristypes.StateDown {
+			t.Errorf("queued message has type %q, peer %q, state %q; want %q, %q, %q",
+				msg.Type, msg.Peer, msg.State, ristypes.MessageTypeState, stateDownPeer, ristypes.StateDown)
+		}
+	default:
+		t.Fatal("the STATE message was not queued for the handler that wants it")
+	}
+}
+
+// streamWithFullStateQueue runs stream, in a goroutine, against a streamer
+// reading from url whose stateHandler's queue is full of STATE messages with
+// no peer. It returns the queue and a channel that gets what stream returns.
+func streamWithFullStateQueue(url string, idleTimeout time.Duration) (
+	queue chan *ristypes.RISMessage, streamErr chan error) {
+	s := New(logger.New(), metrics.New())
+	s.url = url
+	s.idleTimeout = idleTimeout
+	s.RegisterHandler(stateHandler{})
+	queue = s.handlers[0].queue
+	for len(queue) < cap(queue) {
+		queue <- &ristypes.RISMessage{Type: ristypes.MessageTypeState}
+	}
+
+	streamErr = make(chan error, 1)
+	go func() { streamErr <- s.stream(context.Background()) }()
+
+	return queue, streamErr
+}
+
+// TestStreamWaitsForRoomForAStateMessage has the server send one STATE message
+// whose state is down while the queue of the handler that wants it is full. A
+// full queue is where the random drop always drops, and where a message that
+// cannot wait is dropped. The streamer must not drop it: it waits until the
+// handler takes a message off its queue, then queues it.
+func TestStreamWaitsForRoomForAStateMessage(t *testing.T) {
+	const (
+		stillWaitingAfter = 100 * time.Millisecond
+		maxWait           = 5 * time.Second
+	)
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		_, _ = io.WriteString(w, stateDownLine)
+	}))
+	defer srv.Close()
+
+	queue, streamErr := streamWithFullStateQueue(srv.URL, streamIdleTimeout)
+
+	select {
+	case err := <-streamErr:
+		t.Fatalf("stream returned %v while the queue was full: it dropped the STATE message", err)
+	case <-time.After(stillWaitingAfter):
+	}
+
+	<-queue // the handler takes a message, which makes room
+	select {
+	case err := <-streamErr:
+		if !errors.Is(err, errStreamEnded) {
+			t.Fatalf("stream returned %v, want %v", err, errStreamEnded)
+		}
+	case <-time.After(maxWait):
+		t.Fatalf("stream did not queue the STATE message within %s of there being room", maxWait)
+	}
+
+	var last *ristypes.RISMessage
+	for len(queue) > 0 {
+		last = <-queue
+	}
+	if last.Peer != stateDownPeer || last.State != ristypes.StateDown {
+		t.Errorf("last queued message has peer %q, state %q; want %q, %q",
+			last.Peer, last.State, stateDownPeer, ristypes.StateDown)
+	}
+}
+
+// TestStreamStopsWaitingForRoomAtTheIdleTimeout has the server send one STATE
+// message and then hold the response open, while the queue of the handler
+// that wants it stays full. The wait for room must not stall the read loop
+// past its idle timeout: the stream ends as when no line arrives.
+func TestStreamStopsWaitingForRoomAtTheIdleTimeout(t *testing.T) {
+	const (
+		idleTimeout = 50 * time.Millisecond
+		maxWait     = 5 * time.Second
+	)
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.WriteString(w, stateDownLine)
+		w.(http.Flusher).Flush()
+		<-r.Context().Done()
+	}))
+	defer srv.Close()
+
+	_, streamErr := streamWithFullStateQueue(srv.URL, idleTimeout)
+
+	select {
+	case err := <-streamErr:
+		if err == nil || errors.Is(err, errStreamEnded) {
+			t.Errorf("stream returned %v, want the error of a stream dropped as idle", err)
+		}
+	case <-time.After(maxWait):
+		t.Fatalf("stream still waiting for room %s after the idle timeout of %s", maxWait, idleTimeout)
+	}
+}
+
+// TestStopBeforeMessageReachesQueues stops the streamer after the read loop
+// has checked for cancellation but before it hands the message to the handler
+// queues. That is the gap a stop from another goroutine can land in, and it
+// used to end in "send on closed channel". The raw handler runs in that gap on
+// the read loop itself, so calling Stop from it hits the gap every time.
+func TestStopBeforeMessageReachesQueues(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		_, _ = io.WriteString(w, updateLine)
+	}))
+	defer srv.Close()
+
+	s := New(logger.New(), metrics.New())
+	s.url = srv.URL
+	s.RegisterHandler(updateHandler{})
+	s.RegisterRawHandler(func(string) { s.Stop() })
+
+	// Start would run the stream in the background, where the test cannot
+	// wait for it. Setting cancel as Start does lets Stop cancel the stream
+	// run here instead.
+	ctx, cancel := context.WithCancel(context.Background())
+	s.cancel = cancel
+
+	if err := s.stream(ctx); !errors.Is(err, context.Canceled) {
+		t.Fatalf("stream returned %v, want %v", err, context.Canceled)
+	}
+
+	// A second Stop must not close the queues again.
+	s.Stop()
+}
+
+// TestReconnectWhenStreamEnds has the server end the first response
+// normally, as when RIS Live restarts. The streamer must treat that as a
+// disconnect and connect again.
+func TestReconnectWhenStreamEnds(t *testing.T) {
+	endResponse := func(http.ResponseWriter, *http.Request) {}
+	checkReconnect(t, endResponse, streamIdleTimeout)
+}
+
+// TestReconnectWhenStreamGoesIdle has the server hold the first response
+// open without sending anything. The streamer must drop it once the idle
+// timeout passes and connect again.
+func TestReconnectWhenStreamGoesIdle(t *testing.T) {
+	const idleTimeout = 50 * time.Millisecond
+	holdResponse := func(w http.ResponseWriter, r *http.Request) {
+		w.(http.Flusher).Flush()
+		<-r.Context().Done()
+	}
+	checkReconnect(t, holdResponse, idleTimeout)
+}
+
+// TestReconnectWhenServerNeverAnswers has the server accept the first
+// request and never answer it, not even with headers. The streamer must give
+// up on it once the idle timeout passes and connect again.
+func TestReconnectWhenServerNeverAnswers(t *testing.T) {
+	const idleTimeout = 50 * time.Millisecond
+	neverAnswer := func(_ http.ResponseWriter, r *http.Request) {
+		<-r.Context().Done()
+	}
+	checkReconnect(t, neverAnswer, idleTimeout)
+}
+
+// TestStreamNotDroppedWhileLinesArrive has the server send lines well within
+// the idle timeout for several times the timeout, then end the response. Each
+// line must start the idle timeout over, so the stream lasts until the server
+// ends it instead of being dropped as idle.
+func TestStreamNotDroppedWhileLinesArrive(t *testing.T) {
+	const (
+		idleTimeout  = 100 * time.Millisecond
+		lineInterval = idleTimeout / 10
+		sendFor      = 5 * idleTimeout
+	)
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		deadline := time.Now().Add(sendFor)
+		for time.Now().Before(deadline) {
+			_, _ = io.WriteString(w, updateLine)
+			w.(http.Flusher).Flush()
+			time.Sleep(lineInterval)
+		}
+	}))
+	defer srv.Close()
+
+	s := New(logger.New(), metrics.New())
+	s.url = srv.URL
+	s.idleTimeout = idleTimeout
+
+	if err := s.stream(context.Background()); !errors.Is(err, errStreamEnded) {
+		t.Fatalf("stream returned %v, want %v", err, errStreamEnded)
+	}
+}
+
+// checkReconnect runs a streamer against a fake RIS Live server. The first
+// response is served by firstResponse; every later one carries one UPDATE
+// line and then stays open. The streamer must come back for a second
+// response, must not be marked connected when it does, and must handle the
+// UPDATE in it.
+func checkReconnect(t *testing.T, firstResponse http.HandlerFunc, idleTimeout time.Duration) {
+	t.Helper()
+
+	const maxWait = 5 * time.Second
+
+	tracker := metrics.New()
+	connectedAtReconnect := make(chan bool, 1)
+	var requests atomic.Int32
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if requests.Add(1) == 1 {
+			firstResponse(w, r)
+
+			return
+		}
+		select {
+		case connectedAtReconnect <- tracker.IsConnected():
+		default:
+		}
+		_, _ = io.WriteString(w, updateLine)
+		w.(http.Flusher).Flush()
+		<-r.Context().Done()
+	}))
+	defer srv.Close()
+
+	s := New(logger.New(), tracker)
+	s.url = srv.URL
+	s.idleTimeout = idleTimeout
+	s.minBackoff = time.Millisecond
+	handler := updateHandler{handled: make(chan struct{}, 1)}
+	s.RegisterHandler(handler)
+	if err := s.Start(); err != nil {
+		t.Fatalf("Start returned error: %v", err)
+	}
+	defer s.Stop()
+
+	select {
+	case <-handler.handled:
+	case <-time.After(maxWait):
+		t.Fatalf("no message from a second response handled within %s", maxWait)
+	}
+
+	if <-connectedAtReconnect {
+		t.Error("streamer was still marked connected when it came back for a second response")
+	}
+}
+
+// settledGoroutineCount lets transient goroutines finish, then reports the
+// current count.
+func settledGoroutineCount() int {
+	prev := runtime.NumGoroutine()
+	for range 20 {
+		time.Sleep(10 * time.Millisecond)
+		cur := runtime.NumGoroutine()
+		if cur == prev {
+			return cur
+		}
+		prev = cur
+	}
+
+	return prev
+}
+
+// waitForGoroutines waits until the goroutine count drops to target or below.
+func waitForGoroutines(target int) bool {
+	for range 100 {
+		if runtime.NumGoroutine() <= target {
+			return true
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+
+	return false
 }

internal/templates/prefix_detail.html

@@ -283,6 +283,7 @@
                 <div class="origin-item">
                     <a href="/as/{{.ASN}}" class="as-link">AS{{.ASN}}</a>
                     {{if .Handle}} ({{.Handle}}){{end}}
+                    {{if .Description}} {{.Description}}{{end}}
                     <span style="color: #7f8c8d; margin-left: 10px;">{{.PeerCount}} peer{{if ne .PeerCount 1}}s{{end}}</span>
                 </div>
                 {{end}}

internal/version/version.go

@@ -7,7 +7,8 @@ package version
 var (
 	// GitRevision is the git commit hash
 	GitRevision = "unknown"
-	// GitRevisionShort is the short git commit hash (7 chars)
+	// GitRevisionShort is the version the page footer shows: the tag or
+	// short commit hash from `git describe --tags --always`
 	GitRevisionShort = "unknown"
 )
 

script/docker

@@ -1,7 +1,8 @@
 #!/bin/sh
 # script/docker: build the Docker image tagged with the project name.
 # Identical in all repos; the tag comes from script/projectname.
-# Generic: needs no adaptation.
+# --no-cache because the gate phases the final stage depends on are RUN
+# steps, and a cached one is a check that did not run.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -9,7 +10,15 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    docker build -t "$("$SCRIPT_DIR/projectname")" .
+    # Own line: a failing command substitution inside an argument does
+    # not trip `set -e`, so the inline form degrades silently to an
+    # empty constant. The VERSION build argument takes precedence over
+    # the version a build stage derives from the .git in the context.
+    version="$(git describe --tags --always --dirty 2>/dev/null || true)"
+    [ -n "$version" ] || version="unknown"
+    docker build --no-cache \
+        --build-arg VERSION="$version" \
+        -t "$("$SCRIPT_DIR/projectname")" .
 }
 
 main "$@"

script/test

@@ -7,9 +7,9 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    go test -timeout 30s -race -cover ./... || {
+    go test -short -timeout 30s -race -cover ./... || {
         echo "--- Rerunning with -v for details ---"
-        go test -timeout 30s -race -v ./...
+        go test -short -timeout 30s -race -v ./...
         exit 1
     }
 }