routewatch/TODO.md

# Workflow

- branch (from `main`)
- do the work in Next Step
- move Next Step to the top of Completed Steps
- move the top item of Future Steps into Next Step
- commit (`TODO.md` changes in the same commit as the work)
- merge to `main` if the branch is not protected, otherwise open a PR
- push

# Status

RouteWatch is pre-1.0, with no git tags. `main` last took `next` on 2026-10-27,
through https://git.eeqj.de/sneak/routewatch/pulls/166.
https://git.eeqj.de/sneak/routewatch/pulls/202 carries the twelve commits since
then into `main`. It is labelled `merge-ready` and waits for sneak.

The linter and the tests are phases of the Docker build. The Gitea workflow runs
`script/cibuild` on every push. That script checks the formatting of the Go code
and the markdown. Then it builds the image, which runs the two phases.

The image sets memory ceilings for a 5 GiB container (README "Memory"). README
"Running under upaas" says how to run it.

A five-day run of `1c65656` on the live feed, from 27 October to 1 November,
found three problems:

- The prefix handler dropped updates while a peer's session went down
  (https://git.eeqj.de/sneak/routewatch/issues/216).
- The AS handler dropped updates when the feed burst
  (https://git.eeqj.de/sneak/routewatch/issues/217).
- The WHOIS fetcher kept asking a registry that had refused it
  (https://git.eeqj.de/sneak/routewatch/issues/218).

All three are fixed on `next`. So is
https://git.eeqj.de/sneak/routewatch/issues/222, which the third fix brought up.
A 24-hour run of `26d939a` on the live feed is checking whether any handler
still drops updates.

The README rewrite, https://git.eeqj.de/sneak/routewatch/pulls/210, is paused
until sneak has reviewed it. It is part of
https://git.eeqj.de/sneak/routewatch/issues/157.

Two questions wait for sneak: which history the prefix page keeps
(https://git.eeqj.de/sneak/routewatch/issues/161), and which fields the IP
lookup answer gains (https://git.eeqj.de/sneak/routewatch/issues/203).

The state of what remains is kept on
https://git.eeqj.de/sneak/routewatch/issues/86.

# Next Step

Post the outcome of the 24-hour run of `26d939a` on
https://git.eeqj.de/sneak/routewatch/issues/216: whether any handler still drops
updates, and the process's peak memory against 5 GiB. File an issue for each
problem the run finds.

# Completed Steps

- 2026-11-02: `TODO.md` is rewritten from scratch, sentence by sentence, against
  the rules of https://git.eeqj.de/sneak/routewatch/issues/157. Every Completed
  Steps entry keeps its date, its facts and its issue. Status and Next Step
  describe the repo as the tracker shows it (part of #157)
- 2026-11-02: A skipped WHOIS lookup now makes the fetcher wait longer before
  the next one, as a failed lookup does. A lookup is skipped when its registry
  is paused. The longest wait is one minute. The status page does not count a
  skip as a failure. A skip used to leave the wait as it was. Each lookup asks
  IANA before it finds its registry paused. So while most stale ASes belonged to
  a paused registry, the fetcher could ask IANA every second (closes #222)
- 2026-11-02: A peer's session going down no longer stops the prefix handler.
  The handler runs the routing table's `PeerDown` on a goroutine of its own, one
  peer at a time. Meanwhile it goes on taking messages. `PeerDown` holds the
  table's lock for 10,000 prefixes at a time, then lets the lock go for as long
  again. The handler holds back the down peer's later messages until that peer's
  `PeerDown` returns. Then the handler applies them in order, one at a time, and
  takes new messages in between. It holds back at most 20,000 messages. At that
  number, `HandleMessage` waits until one of them is applied. When `Stop` runs
  past its deadline, it logs how many held-back messages were not applied
  (closes #216)
- 2026-11-02: RouteWatch pauses a registry's WHOIS server for an hour after the
  server refuses a query. The registries are the five RIRs (the regional
  Internet registries) and NIC.br. A refused or reset connection is a refusal.
  So is an answer with an `%ERROR:201:` or `%ERROR:202:` line. Lookups at the
  other servers go on. An AS whose registry is paused is looked up after the
  pause. IANA is never paused, because a pause of IANA would stop every lookup.
  A refusal by IANA is an ordinary failure. NIC.br is also paused for an hour
  after it says RouteWatch has passed its query limit. Before, the fetcher asked
  a server again within seconds of a refusal (closes #218)
- 2026-11-02: The AS handler never waits for a database write. Its batch holds
  one entry per AS, with the earliest and the latest time of its updates. So the
  batch no longer grows with the feed's rate. It used to hold one entry for each
  AS of each path. At 300,000 entries it waited for the write in progress. In a
  burst of the feed its queue then filled, and the streamer dropped messages for
  it (closes #217)
- 2026-10-27: The tests of `internal/routewatch` no longer fail on a loaded
  host. Five of them gave `HandleMessage` two seconds to apply a full prefix
  batch. Under the race detector that can take longer. A test now waits up to 15
  seconds for each step it expects. The tests of the handlers' limits now give
  the handlers small limits. So the whole package runs well inside its 90-second
  limit (closes #213, #215)
- 2026-10-27: The server works out the home page's cards every minute until it
  stops. It used to work them out only once, at startup. The end of the context
  given to `Start` stopped the refreshes (closes #211)
- 2026-10-27: README "Rationale" says why RouteWatch exists. It answers our
  other services' questions about IP addresses, from its own routing table and
  the WHOIS details it keeps. The section still says what RIS Live does not give
  (closes #204)
- 2026-10-27: Every JSON answer carries `@meta`. A panic on a JSON route answers
  500 with the JSON error body. `/status.json` and the health check answer 405
  with the JSON error body to any method they do not take. The 500 and the 405
  used to have an empty body. The home page's IP lookup shows the whole JSON
  answer, `@meta` included. It used to show only the answer's `data`, or only
  the message of an error answer. A test checks `@meta` on every JSON route, in
  its successes and its errors (closes #201)
- 2026-10-27: Every value with a unit in a JSON answer is a number. The unit is
  at the end of the field name. `@meta.execution_time` is now
  `execution_time_ms`. In the stats, `uptime` is now `uptime_seconds`,
  `connection_duration` is now `connection_duration_seconds`, and `memory_usage`
  is now `memory_usage_bytes`. `whois_stats.current_interval` is now
  `whois_stats.current_interval_seconds`. They used to be strings such as "12
  ms", "1h18m34s" or "1.1 GB". `connection_duration_seconds` is null while the
  feed is not connected. `API_POLICIES.md` is vendored from `sneak/prompts`, and
  `REPO_POLICIES.md` is re-vendored (closes #199)
- 2026-10-27: Every result of the IP lookup has the same fields. A field without
  a value is null. It used to be left out. An address with no route in the
  routing table has every route and AS field set to null. `ptr` is an empty list
  when there are no PTR names. The new field `num_origins` gives the number of
  origin ASes of the netblock, and `origin_asns` gives which they are (closes
  #200)
- 2026-10-27: With `TRUSTED_PROXIES` unset, the server trusts reverse proxies at
  the private addresses of RFC 1918. `/ip/`, the home page's `curl` card and the
  request log then give the client's address from `X-Forwarded-For`. They used
  to give the proxy's address. A list in `TRUSTED_PROXIES` replaces the default.
  `TRUSTED_PROXIES` set but empty trusts no proxy (closes #198)
- 2026-10-27: The home page has cards with figures of the routing table. One
  card shows the newest and the oldest kept route. One shows the newest and the
  oldest updated AS. One shows the AS with the most prefixes. One shows the ASes
  with a single prefix. One shows fifteen well-known networks. Two cards count
  the bogon announcements and the prefixes with more than one origin AS. They
  link to the new pages `/bogons` and `/multiple-origins`, which list them. A
  new package, `internal/bogon`, tells which prefixes and AS numbers are
  reserved. The server works the figures out once a minute (closes #154)
- 2026-10-27: The per-peer route tables are gone, with the code that wrote,
  counted and read them. The prefix handler applies each update to the routing
  table in memory. It writes the table's changes every second. It also stores
  each new prefix with its first-seen time. The image's memory limits fit a full
  routing table of about 1 GB. `GOMEMLIMIT` is 2.5 GiB. The writing connection's
  page cache is 512 MiB. SQLite's soft and hard heap limits are 768 MiB and 1
  GiB (closes #122)
- 2026-10-27: The pages, the API and the stats read every route from the routing
  table in memory. For a prefix with several origin ASes, the IP lookup gives
  the one most peers carry. Its `last_seen` is the newest kept route's time. The
  prefix page and API list every peer that carries the prefix. Only the kept
  routes show an AS path, a next hop and a time. The stats count the origins
  whose kept routes were all withdrawn, in `origins_without_kept_route` (part of
  #122)
- 2026-10-27: The prefix, AS and peer handlers make a timed write on every tick
  of their timers. The prefix handler's timer ticks every second. The other two
  tick every two seconds. They used to skip every other tick. A full batch's
  write restarts the timer. So the next timed write comes one interval after
  that write began (closes #192)
- 2026-10-27: Once the stop deadline has passed, the AS, peer and peering
  handlers start no write either. Before, a full batch or a timer tick could
  wait while a write ran past the deadline. Either could then start one more
  write. The flush goroutines of the prefix, AS and peer handlers now run the
  same code (closes #189)
- 2026-10-27: Once the stop deadline has passed, the prefix handler starts no
  flush. Before, a batch that filled during a late write could still be written
  after the deadline (closes #188)
- 2026-10-27: The prefix handler applies each update to the routing table in
  memory. It writes the table's changes to the database every second. A write
  takes at most 20,000 changed pairs of prefix and origin AS. The rest follow in
  the next writes. A failed write is written again later. Startup reads the
  table before the streamer connects. The pages still read the per-peer route
  tables (part of #122)
- 2026-10-27: The database keeps a copy of the whole routing table in a new
  `routes` table, one row per prefix and origin AS. The peers' numbers are in a
  new `route_peers` table. One function writes the pairs that changed in memory.
  Another reads the whole table back into memory at startup. Nothing uses them
  yet (part of #122)
- 2026-10-27: A new package, `internal/routetable`, holds the whole routing
  table in memory. For each prefix and origin AS it keeps the peers that carry
  it, one bit per peer. It also keeps the two newest of their routes. Nothing
  uses it yet (part of #122)
- 2026-10-27: Each result of the IP lookup lists the public blocklists the
  address is on, in `blocklists`. The lists are DShield, Feodo Tracker, two
  FireHOL lists, Spamhaus DROP and the Tor exit list. RouteWatch downloads each
  list on its own schedule and answers from copies in memory. The copies are
  also kept in the state directory's `blocklists` directory. IP lookup answers
  carry `Cache-Control`. An address with no route now has a result too, without
  route fields. So the IP lookup no longer answers 404 (closes #158)
- 2026-10-27: The home page has an IP information API card. It shows the `curl`
  command that looks up the visitor's own address at `/ip/{addr}`. It also shows
  that command's live answer (closes #156)
- 2026-10-27: On the AS page, a click on the heading of the IPv4 or the IPv6
  prefix list folds or unfolds the list. Both lists start open (closes #155)
- 2026-10-27: The AS page lists its IPv4 and its IPv6 prefixes by mask length,
  shortest first. Prefixes of one mask length are listed by address. The lists
  used to be in address order alone (closes #153)
- 2026-10-27: On `/` and `/status`, a spinner beside the status turns one frame
  each time the stats show more messages than the time before. After three
  refreshes with no new messages, the page shows "stale" in red instead. Next to
  it is the time since the last fresh answer (closes #152)
- 2026-10-27: The WHOIS details of a Brazilian AS keep their accented letters.
  LACNIC's answer for such an AS is NIC.br's answer with each accented letter
  replaced. NIC.br is Brazil's registry. The details now come from NIC.br's own
  server, `whois.registro.br`. When that query fails, the details from LACNIC's
  answer are kept and a warning is logged. RouteWatch stops asking NIC.br for an
  hour after NIC.br says RouteWatch is over its query limit (closes #174)
- 2026-10-27: `make asupdate` stops with an error when the download of `as.csv`
  breaks off. The generator used to retry the failed read forever. A record that
  does not parse is still logged and skipped (closes #177)
- 2026-10-27: `make asupdate` runs the new `script/asupdate`. It replaces the AS
  list built into RouteWatch only when the generator succeeds and finds at least
  one AS. A failed download used to replace the list with an empty file. The
  generator reads `as.csv` from `ipverse/as-metadata`, the source's new name
  (closes #173)
- 2026-10-27: The WHOIS details of an AS at RIPE, APNIC or AFRINIC come only
  from its `aut-num` object and the organisation object it names. RIPE and APNIC
  start their answer with the `as-block` object of the AS's block. Its dates
  were stored as the AS's (closes #168)
- 2026-10-27: AS names keep their accented letters. The AS list built into
  RouteWatch is rebuilt from today's `as.csv`, which added a country code
  column. That file no longer lists AS 0 or the documentation AS numbers. A
  WHOIS answer that is not valid UTF-8 is decoded as Latin-1 before it is parsed
  and stored. RIPE and APNIC send Latin-1 (closes #165)
- 2026-10-27: The Age column on the AS and prefix pages reads in words, such as
  "5 minutes ago" or "2 weeks ago". It used to print Go durations such as
  "360h0m0s ago". An age under a minute reads in seconds. An age over a month
  reads in months or years instead of a date (closes #163)
- 2026-10-26: A write to a stored AS, peering or peer keeps the earlier of the
  two first-seen times. It keeps the later of the two last-seen times. An old
  update from a collector catching up on a backlog no longer moves last seen
  back (closes #162)
- 2026-10-26: The status page shows "Route Churn/min". That is the number of
  prefix announcements and withdrawals from all peers in the last full clock
  minute. `/api/v1/stats` reports it as `route_churn_per_min` in `stream`. It
  replaces the moving average `route_churn_per_sec`. The messages and updates
  per second on `/` and `/status` are whole numbers (closes #160)
- 2026-10-26: The WHOIS fetcher backs off more slowly. A failure makes its wait
  1.5 times as long, up to one minute instead of five. Its queries to RIPE,
  APNIC and AFRINIC leave out person and role objects. RIPE counts those objects
  against a daily limit per address. A refused query is logged with the RIR's
  error line (closes #159)
- 2026-10-26: The home page's AS name search works. It lists the ASes whose
  handle or description holds the text, as links to their pages. The new
  `/api/v1/search/as` answers it. The search ignores case. When the database has
  no record of an AS, its page takes the handle and description from the AS list
  built into RouteWatch. It still lists the AS's prefixes (closes #151)
- 2026-10-19: README "HTTP Endpoints" lists every route with what it answers.
  README "Database Schema" matches `schema.sql`. The rest of the README matches
  the code. This file is brought up to date (closes #72)
- 2026-10-19: Route writes are cheaper. The live route and prefix tables lose
  their random UUID keys. The prefix tables lose their duplicate index. A route
  update sets only the columns that change. Every write goes through one
  connection with a page cache of 1 GiB (README "Memory"). A benchmark writes
  the prefix handler's largest batch faster than the feed sends it (closes #96)
- 2026-10-19: The checkpoint of the WAL (SQLite's write-ahead log), the
  incremental vacuum and `ANALYZE` take the database lock that every batch write
  holds. So a vacuum no longer fails with "database is locked". An `ANALYZE` no
  longer makes a batch write lose its updates. `ANALYZE` runs as
  `PRAGMA optimize` with an analysis limit (closes #94)
- 2026-10-19: Shutdown stops the streamer first. Each handler then writes
  everything left on its queue before it stops. So the updates waiting there are
  no longer lost (closes #69)
- 2026-10-19: A path that ends in an AS set of several members has origin AS 0,
  which means no known origin. It used to have the set's last member as its
  origin. The set adds no peerings. The pages show such a route as having no
  known origin (closes #75)
- 2026-10-19: `bgp_peer_count` drops to 0 when the last peer goes down (closes
  #92)
- 2026-10-19: `bgp_peer_count` counts every peer the feed has heard from. It
  used to count only the peers whose session opened since startup. It drops a
  peer whose session goes down (closes #74)
- 2026-10-19: The shared files are re-vendored from `sneak/prompts` at
  `0653579`. The linter is `golangci-lint` v2.14.0 with its configuration. Lint
  and test are `Dockerfile` phases that keep Go's and `golangci-lint`'s caches.
  `make fmt` also formats the markdown with `prettier`. The agent guidance moves
  to `AGENTS.md`. The code is fixed for what the new linter configuration finds
  (closes #52)
- 2026-10-19: The streamer reads feed lines up to 1 MiB. A line over 64 KiB used
  to end the connection (closes #76)
- 2026-10-19: A peer's live routes are removed when its BGP session goes down.
  `STATE` messages are never dropped when a queue is full. One that finds its
  queue full waits for room ahead of the handler's other messages (closes #56)
- 2026-10-19: The prefix-length pages pick their sample with a bounded number of
  index lookups. They used to read every route of that length. They list each
  prefix once (closes #66)
- 2026-10-19: A request past its time limit answers 504 instead of 408.
  `/api/v1/stats` answers 504 instead of 500 when its read runs out of time
  (closes #70)
- 2026-10-19: The AS, peer and prefix handlers write each batch outside the lock
  their message handling needs. So messages keep coming off their queues during
  a write. Meanwhile the next batch grows to at most ten batch sizes (closes
  #65)
- 2026-10-19: A live route is identified by prefix and peer. So an announcement
  with a new origin AS replaces the peer's route. A withdrawal removes it
  whatever its origin AS (closes #55)
- 2026-10-14: The streamer reconnects when RIS Live ends the stream or sends
  nothing for 60 seconds. The health check reports the feed disconnected
  meanwhile (closes #53)
- 2026-10-14: The prefix page takes the names of the origin ASes from the prefix
  query. It used to read every route of each origin AS (closes #67)
- 2026-10-14: The daemon exits with status 1 when its web server cannot listen
  on its port. It used to run on without a web server (closes #73)
- 2026-10-14: The prefix pages parse the prefix before looking it up. One that
  does not parse answers 400. Any valid way of writing a prefix finds its routes
  (closes #71)
- 2026-10-14: The IP lookup ignores routes shorter than /8 for IPv4 and /16 for
  IPv6. So a default route is no longer named as an address's owner (closes #57)
- 2026-10-14: A prefix batch keeps each peer's last update for a prefix. It used
  to keep one update per prefix across all peers (closes #54)
- 2026-10-14: `reconnect_count` in `/api/v1/stats` counts every reconnect
  (closes #68)
- 2026-10-03: `/api/v1/stats` serves the prefix distribution from memory. The
  distribution is 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.
  The setting goes in the connection string, so it is set before the file is
  first written. 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. 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
  into the page footer. It used to stamp `unknown`. The value comes from
  `git describe --tags --always`. `.dockerignore` sends `.git` without
  `.git/config`. A `VERSION` build argument takes precedence. `make build`
  stamps the same value (closes #46)
- 2026-09-29: The entrypoint creates the data directory if it is missing. It
  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. So they stay out of the source
  archive in the image (closes #39)
- 2026-09-29: The README's first line names the MIT licence and the author. The
  License section says MIT and links `LICENSE`. An Author section is added. This
  file is brought up to date (closes #38)
- 2026-09-29: `LICENSE` is added, with the MIT licence (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. 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. It gets the
  whole wait `docker stop` allows, up to its own 60-second limit (closes #33)
- 2026-09-28: RouteWatch is 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 gains a "Running under upaas" section (closes #31)
- 2026-09-22: The database statistics are kept in memory. The counts are seeded
  at startup and adjusted on every write. The oldest and newest route times come
  from a lookup at each end of an index. `/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 the number of glibc malloc
  arenas. So memory outside the Go runtime no longer grows with the core count
  (closes #23)
- 2026-09-21: The image sets `GOMEMLIMIT=1536MiB`. README "Memory" gives 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 are fixed. The stats handlers leaked after a
  timeout. The streamer's tickers leaked 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` is added. A Gitea workflow runs `script/cibuild`
  on every push (closes #14)
- 2026-09-21: The peering handler's AS-path map holds at most 500,000 paths.
  Every 30 seconds it is swapped for an empty one instead of copied (closes #10)
- 2026-09-21: SQLite's memory is bounded across the whole connection pool. Each
  connection has a 64 MiB page cache. The heap limits are 1 GiB soft and 1.5 GiB
  hard (closes #8)
- 2026-09-21: The Docker build runs the format check, the linter and the tests.
  Linting runs in a separate stage on a `golangci-lint` image pinned by digest
  (closes #5)
- 2026-09-21: `make test` skips the live feed test, with `-short`. So
  `make check` no longer depends on the network (closes #2)
- 2026-07-07: The scripts-to-rule-them-all layout is adopted. `script/` holds
  the entrypoints, and the `Makefile` targets call them. README gains an
  "Entrypoints" section
- 2026-02-22: The repo is brought in line with the repo policies. The required
  policy files are added. `.gitignore` is updated. The `Makefile` gains
  `fmt-check`, `check`, `docker` and `hooks` targets. The Go code is formatted
  with `gofmt`. The work was on the branch `repo-policies-compliance`, unmerged
  when this entry was written
- 2026-01-01: The WAL is checkpointed every 5 seconds, and at startup with a log
  line. Checkpoints run in `TRUNCATE` mode. This fixed slow queries
- 2025-12-31: The pages get a navigation bar and a home page with a search. The
  status page shows the oldest and newest route times. The WHOIS stats query
  handles `NULL`. The container runs as the `routewatch` user with the right
  state directory
- 2025-12-30: HTTP requests are logged as structured log lines. The HTTP
  timeouts are longer. Prefix URLs with a slash in them route correctly. The
  status page gets more metrics and a footer
- 2025-12-29: The `Dockerfile` builds in stages and puts a source archive in the
  image. SQLite reclaims space with incremental vacuum, which does not block
- 2025-07-27: The first commit: RouteWatch, a BGP stream monitor

# Future Steps

- Merge https://git.eeqj.de/sneak/routewatch/pulls/210 once sneak has reviewed
  it. The last PR for https://git.eeqj.de/sneak/routewatch/issues/157 to merge
  closes that issue.