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The nine findings: the heap figure keeps the old README's meaning; the
Makefile sentence names the three targets that call no script; the five
fields /api/v1/stats adds are a list; the test comment names README
"JSON API"; the X-Forwarded-For readers are a list, with short sentences
after it; the AS page's peers are the ASes next to it in AS paths; CIDR
ranges and the default route are explained; handle and description are
field names; the TODO entry is one sentence.

The sweep of every sentence defined feed, carry, IANA, multicast,
handler, streamer, reverse proxy and goroutine at first use, split the
list of parts, and named the 404 of an unknown page path.

Model: fable-5-1
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@@ -15,7 +15,8 @@ path.
RouteWatch does three things:
- It streams BGP updates from the RIPE RIS Live service.
- It streams BGP updates from the RIPE RIS Live service. This document calls
that stream the feed.
- It applies them to a routing table that it keeps in memory, with a copy in a
SQLite database.
- It serves web pages and a JSON API that answer from that table.
@@ -27,9 +28,11 @@ about IP addresses. A service asks RouteWatch instead of working the answer out
for itself.
RIPE runs route collectors around the world. Many routers, the RIS peers, send
the collectors their routes over BGP sessions. RIS Live streams every change the
collectors receive, as it happens. RouteWatch applies those changes to its own
routing table. From that table it sees directly:
the collectors their routes. The connection between a peer and a collector is a
BGP session. A peer carries a prefix when the peer has a route to that prefix.
RIS Live streams every change the collectors receive, as it happens. RouteWatch
applies those changes to its own routing table. From that table it sees
directly:
- which AS each IP address is routed to
- which announced prefix holds the address, and how big that prefix is
@@ -89,8 +92,8 @@ database keeps the table across restarts.
## HTTP
The server listens on `PORT`, `8080` by default. Every route answers `HEAD` as
it answers `GET`, without the body.
The server listens on `PORT`, `8080` by default. Every page and API path answers
`HEAD` as it answers `GET`, without the body.
The pages and the API read routes from the routing table in memory. For each
prefix and origin AS, the table keeps the two newest routes in full, with their
@@ -104,7 +107,7 @@ and origin AS can have two kept routes, one or none.
- `/`: the home page. Its top row shows these figures, refreshed every 5
seconds:
- whether the feed is connected
- the number of live routes, ASes, prefixes and BGP peers
- how many routes, ASes, prefixes and peers there are
- the route updates per second
Below the figures are a lookup by AS number, a search of AS names and a
@@ -118,22 +121,24 @@ and origin AS can have two kept routes, one or none.
- how many ASes originate a single prefix, and the newest kept route of
those ASes
- the number of bogon announcements, linked to `/bogons`. A bogon
announcement is a route whose prefix or origin AS is reserved.
announcement is a route whose prefix or origin AS is reserved, as the
rules below say.
- the number of prefixes with more than one origin AS, linked to
`/multiple-origins`
- fifteen well-known networks, such as Apple, Google, Cogent and MIT, each
with its number of prefixes and the age of its newest kept route, newest
first
RouteWatch works these figures out once a minute, so they can be a minute
old. Until the first figures are ready, the page says that they are being
worked out.
RouteWatch works out the figures on these cards once a minute, so they can
be a minute old. Until the first figures are ready, the page says that they
are being worked out.
- `/as/{asn}`: an AS, the prefixes it originates and the ASes it peers with. The
prefixes come in two lists, IPv4 and IPv6, shortest mask length first. An AS
has a handle, a short name such as `GOOGLE`, and a description, such as
`Google LLC`. When the database has no record of the AS, both come from the AS
list built into RouteWatch. The page then shows no first-seen date.
- `/as/{asn}`: an AS, the prefixes it originates and the ASes next to it in AS
paths. The prefixes come in two lists, IPv4 and IPv6, shortest mask length
first. An AS has a handle, a short name such as `GOOGLE`, and a description,
such as `Google LLC`. When the database has no record of the AS, both come
from the AS list built into RouteWatch. The page then shows no first-seen
date.
- `/prefix/{prefix}/{length}`: a prefix, such as `/prefix/192.0.2.0/24`, with
its origin ASes and every peer that carries it. Only the kept routes show an
AS path, a next hop and a time. The next hop is the router the peer sends the
@@ -157,11 +162,13 @@ and origin AS can have two kept routes, one or none.
A prefix is reserved when it lies inside one of these:
- a block that the IANA special-purpose address registries mark as not globally
reachable
- the multicast space, `224.0.0.0/4` and `ff00::/8`
reachable. The IANA is the body that hands out the internet's address space
and AS numbers.
- the multicast blocks, `224.0.0.0/4` and `ff00::/8`. A multicast address stands
for a group of receivers, not for one host.
A few blocks that may be announced lie inside reserved blocks. The most specific
block that holds the prefix decides.
A few blocks that may be announced lie inside reserved blocks. Of the blocks
that hold the prefix, the one with the longest mask length decides.
An AS number is reserved when it is one of these:
@@ -185,7 +192,7 @@ also carries an `@meta` object:
Every value with a unit is a number, and the unit ends the field name. Examples
are `_ms`, `_seconds`, `_bytes`, `_per_sec` and `_per_min`.
The routes:
The paths:
- `GET /api/v1/ip/{ip}`: what RouteWatch knows about each address in `{ip}`. See
IP lookup below.
@@ -194,15 +201,16 @@ The routes:
the request came from. For a request from a trusted proxy, it is the client
address in `X-Forwarded-For` (see `TRUSTED_PROXIES` in Configuration).
- `GET /api/v1/as/{asn}`: the AS and the prefixes it originates. `data` holds:
- `asn`: the AS, with its handle, description, `first_seen` and `last_seen`
- `asn`: the AS, with its `handle`, `description`, `first_seen` and
`last_seen`
- `ipv4_prefixes` and `ipv6_prefixes`: the prefixes it originates, each with
`last_updated`, the time of its newest kept route with the AS
- `total_count`: how many prefixes the two lists hold together
`last_updated` is left out when the kept routes of the prefix with the AS
were all withdrawn. When the database has no record of the AS, its handle
and description come from the AS list built into RouteWatch. The answer then
has no `first_seen` or `last_seen`.
were all withdrawn. When the database has no record of the AS, its `handle`
and `description` come from the AS list built into RouteWatch. The answer
then has no `first_seen` or `last_seen`.
- `GET /api/v1/prefix/{prefix}/{length}`: the prefix and its routes. `data`
holds:
@@ -212,7 +220,9 @@ The routes:
- `peer_count` and `origin_count`: how many routes and how many origin ASes
there are
Only the kept routes have `as_path`, `next_hop` and `last_updated`.
A route has `prefix`, `mask_length`, `ip_version`, `origin_asn` and
`peer_ip`. Only the kept routes also have `as_path`, `next_hop` and
`last_updated`.
- `GET /api/v1/search/as?q={text}`: the ASes whose handle or description
contains `{text}`, ignoring case. `data` holds:
@@ -226,8 +236,8 @@ The routes:
[ipverse/as-metadata](https://github.com/ipverse/as-metadata). So a match
can be an AS that the database has no record of.
- `GET /status.json`: figures of the feed, the memory, the database and the
routing table. The figures whose names do not say what they mean:
- `GET /status.json`: the daemon's figures. The figures whose names do not say
what they mean:
- `uptime_seconds`: the seconds since the feed last connected, or 0 when it
has never connected
- `memory_usage_bytes`: the size of the Go heap in use
@@ -239,12 +249,17 @@ The routes:
that peers carry but whose kept routes were all withdrawn
- `whois_stats.current_interval_seconds`: the WHOIS fetcher's wait between
two fetches, which can include a fraction of a second
- `GET /api/v1/stats`: the `/status.json` figures plus `reconnect_count`, and
figures of the garbage collector in `gc`, of the stream in `stream` and of the
handler queues in `handler_stats`. `connection_duration_seconds` is the
seconds the feed has been connected, or null while it is not connected.
`stream.route_churn_per_min` is the number of prefix announcements and
withdrawals, from all peers, in the last full clock minute.
- `GET /api/v1/stats`: the `/status.json` figures and five more:
- `reconnect_count`: how many times the feed has reconnected since the start
- `connection_duration_seconds`: the seconds the feed has been connected, or
null while it is not connected
- `gc`: figures of the garbage collector, the part of the Go runtime that
frees memory no longer in use
- `stream`: figures of the feed. `stream.route_churn_per_min` is the number
of prefix announcements and withdrawals, from all peers, in the last full
clock minute.
- `handler_stats`: figures of the handlers' queues. The handlers are the
four parts that take the feed's messages (see Design).
- `GET /.well-known/healthcheck.json`: the health check. It answers 200 when the
database answers and the feed is connected, otherwise 503. `data.status` is
`ok` or `error`, and `data.checks` says which check failed. The 503 answer
@@ -266,7 +281,8 @@ address. Every entry has the same fields:
Every other field is about the address's live route. Each is null when the
address has no live route:
- `netblock`: the most specific prefix that holds the address
- `netblock`: the most specific prefix that holds the address, the one with the
longest mask length
- `mask_length`: the netblock's mask length
- `ip_version`: the netblock's IP version, 4 or 6
- `num_peers`: the number of peers that carry the netblock
@@ -290,7 +306,8 @@ database does not have it:
- `address`: the organisation's postal address
- `country_code`: the organisation's country code
- `abuse_email`: the address that takes abuse reports for the AS
- `rir`: the regional internet registry of the AS
- `rir`: the regional internet registry that holds the AS, one of `ARIN`,
`RIPE`, `APNIC`, `LACNIC` and `AFRINIC`
When a host name fails, `errors` lists it with the reason. A name that does not
resolve is reported as `could not resolve host name`. A name with no public
@@ -320,14 +337,15 @@ shortest blocklist interval. The answer for the caller's own address (`/ip/`) is
- an AS that originates no prefix and has no record in the database or in
the AS list built into RouteWatch
- a prefix that no peer carries
- under `/api/v1` and `/ip/`, a path that matches no route, with the message
- under `/api/v1` and `/ip/`, a path that matches nothing, with the message
`Not found`
- any other path that matches nothing, with the text `404 page not found`
- 405, with the message `Method not allowed`, for `POST`, `PUT`, `PATCH`,
`DELETE`, `OPTIONS`, `TRACE` or `CONNECT` on these routes:
- the routes under `/api/v1` and `/ip/`
`DELETE`, `OPTIONS`, `TRACE` or `CONNECT` on these paths:
- the paths under `/api/v1` and `/ip/`
- `/status.json`
- `/.well-known/healthcheck.json`
- 500: an internal error. The JSON routes say only `Internal server error`. The
- 500: an internal error. The JSON paths say only `Internal server error`. The
detail goes to the log.
- 504: `Request timeout`. A request may take 30 seconds. The database reads
behind `/status.json` and `/api/v1/stats` may take 4 seconds.
@@ -425,38 +443,45 @@ command-line flags.
- `PORT`: the port the HTTP server listens on. A whole number from 1 to 65535.
Default `8080`.
- `DEBUG`: set it to `routewatch` for debug logging. The daemon then also logs a
`System stats` line every 60 seconds, with the goroutine count and the Go
memory figures. Default empty.
`System stats` line every 60 seconds, with the Go memory figures and the
number of goroutines, Go's lightweight threads. Default empty.
- `TRUSTED_PROXIES`: the reverse proxies whose `X-Forwarded-For` header the
server believes. See below. Default: the private ranges of RFC 1918.
- `XDG_DATA_HOME`: the base of the state directory on Linux and the BSDs, when
RouteWatch does not run as root. It must be an absolute path. The Docker image
sets `/var/lib`.
- `GOMEMLIMIT`: the Go runtime's soft memory limit. The Docker image sets
`2560MiB`. See Memory.
server believes. A reverse proxy is a server in front of RouteWatch that
passes requests on to it. See below. Default: the private ranges of RFC 1918.
- `XDG_DATA_HOME`: the base of the state directory (see below) on Linux and the
BSDs, when RouteWatch does not run as root. It must be an absolute path. The
Docker image sets `/var/lib`.
- `GOMEMLIMIT`: the ceiling the Go runtime keeps the program's memory under. The
Docker image sets `2560MiB`. See Memory.
- `MALLOC_ARENA_MAX`: how many memory pools, called arenas, the C library may
create. The Docker image sets `2`. See Memory.
`PORT`, `XDG_DATA_HOME` or `TRUSTED_PROXIES` set to an invalid value stops the
start with an error and a non-zero exit. The Docker image's entrypoint refuses a
`MALLOC_ARENA_MAX` that is not a positive whole number. An empty variable counts
as unset. `TRUSTED_PROXIES` is the one exception: set but empty, it makes the
server trust no proxy.
The start fails, with an error and a non-zero exit, when `PORT`, `XDG_DATA_HOME`
or `TRUSTED_PROXIES` has an invalid value. In the Docker image, `entrypoint.sh`
refuses a `MALLOC_ARENA_MAX` that is not a positive whole number. An empty
variable counts as unset. `TRUSTED_PROXIES` is the one exception: set but empty,
it makes the server trust no proxy.
`TRUSTED_PROXIES` works like this:
- When it is not set, the server trusts `10.0.0.0/8`, `172.16.0.0/12` and
`192.168.0.0/16`.
- When it lists addresses and CIDR ranges, comma-separated, such as
- When it lists addresses and prefixes, comma-separated, such as
`10.0.0.0/8,192.0.2.1`, the server trusts those instead.
- When it is set but empty (`TRUSTED_PROXIES=`), the server trusts no proxy.
For a request from a trusted proxy, the request log, `/ip/` and the home page's
`curl` card use the last address in `X-Forwarded-For` that is not a trusted
proxy. Each proxy adds the address it received the request from to the end of
the header. The entries before that are whatever the client sent. For a request
from any other address, they use the address the request came from, whatever
headers it carries. `X-Real-IP` and `True-Client-IP` are not read.
Three parts of RouteWatch read `X-Forwarded-For`:
- the request log
- `/ip/`
- the home page's `curl` card
For a request from a trusted proxy, they use the last address in the header that
is not a trusted proxy. Each proxy adds, at the end of the header, the address
that sent it the request. The entries left of the client's address were written
by the client. For a request from any other address, they use the address the
request came from, whatever headers it carries. `X-Real-IP` and `True-Client-IP`
are not read.
The state directory holds the database, `db.sqlite`, and the blocklist copies:
@@ -480,24 +505,27 @@ a memory limit of 5 GiB and swap disabled:
docker run --memory=5g --memory-swap=5g ...
```
That leaves room above the ceilings for spikes and for the kernel's page cache.
The 5 GiB leaves room above the ceilings for spikes and for the kernel's cache
of the database file.
The ceilings add up to 3.7 GiB:
- The Go heap: a 2.5 GiB soft limit, `GOMEMLIMIT=2560MiB`, set by the image. The
routing table takes about 700 bytes for each prefix and origin AS pair. A full
table has about 1.4 million pairs, so it takes about 1 GB. The handlers'
batches and queues take up to about 0.5 GiB. The remaining 1 GiB is room for
the garbage collector. With much less, it would run almost all the time.
- The Go heap, the memory the Go program allocates: a 2.5 GiB soft limit,
`GOMEMLIMIT=2560MiB`, set by the image. The routing table takes about 700
bytes for each prefix and origin AS pair. A full table has about 1.4 million
pairs, so it takes about 1 GB. The rest of the heap takes up to about 0.5 GiB,
most of it the handlers' batches and queues (see below). The remaining 1 GiB
is room for the garbage collector, which frees memory the program no longer
uses. With much less, it would run almost all the time.
- SQLite: 1 GiB, set in the code. The connection that does every write has a 512
MiB page cache, the database pages it keeps in memory. It keeps the pages the
writes touch from one write to the next. The `routes` table of a full routing
table takes about 450 MB, so its pages fit. Each of the 9 reading connections
has 16 MiB. A 768 MiB soft heap limit sits above the caches, so it does not
shrink them. A 1 GiB hard heap limit caps the SQLite library.
MiB page cache: the database pages it keeps in memory from one write to the
next. The `routes` table of a full routing table takes about 450 MB, so its
pages fit. Each of the 9 reading connections has 16 MiB. A 768 MiB soft heap
limit sits above the caches, so it does not shrink them. A 1 GiB hard heap
limit caps the SQLite library.
- About 0.2 GiB for everything else in the runtime.
The SQLite library gets its memory from the C library, glibc. glibc keeps freed
The SQLite library gets its memory from glibc, the C library. glibc keeps freed
memory in pools called arenas, and hands it back to the kernel slowly. It
creates up to eight arenas per processor core. So on a host with many cores the
process holds far more memory than SQLite uses. The image sets
@@ -510,15 +538,17 @@ What happens at each limit:
garbage more often rather than growing further.
- The SQLite soft heap limit: SQLite recycles its page cache instead of
allocating more.
- The SQLite hard heap limit: a statement fails with an out-of-memory error,
which the handler logs. The prefix handler writes the routing table's changes
again in a later write. Everything else in the failed write is dropped. The
process keeps running.
- The handler queues: each of the four handlers has a queue of at most 20,000
messages. When a queue fills, the streamer drops messages instead of waiting.
The exception is a `STATE` message, which it holds, in feed order, until there
is room. A `STATE` message says that a peer's BGP session changed state, for
example went down. These are a few hundred bytes each, about ten a second.
- The SQLite hard heap limit: a database statement fails with an out-of-memory
error, which the handler logs. The prefix handler writes the routing table's
changes again in a later write. Everything else in the failed write is
dropped. The process keeps running.
- The handler queues: the handlers are the four parts that take the feed's
messages (see Design). Each has a queue of at most 20,000 messages. When a
queue fills, the streamer drops messages instead of waiting. The streamer is
the part that reads the feed. The exception is a `STATE` message, which it
holds, in feed order, until there is room. A `STATE` message says that a
peer's BGP session changed state, for example went down. These are a few
hundred bytes each, about ten a second.
- The handler batches: while the AS, peer or prefix handler writes a batch to
the database, the updates that arrive collect in its next batch. That batch
stops at ten times the batch size:
@@ -538,7 +568,7 @@ many cores.
## Running under upaas
What the [upaas](https://git.eeqj.de/sneak/upaas) app needs:
What [upaas](https://git.eeqj.de/sneak/upaas), the deployment tool, needs:
- Container port: `8080`.
- Volume: one, at the container path `/var/lib/berlin.sneak.app.routewatch`.
@@ -558,19 +588,25 @@ What the [upaas](https://git.eeqj.de/sneak/upaas) app needs:
cannot reach RIS Live never becomes healthy.
- Stop grace: upaas gives the container 10 seconds between `SIGTERM` and
`SIGKILL`, as `docker stop` does by default. The daemon gives its parts 8
seconds to stop and then exits. A stop still not done after 9 seconds ends
with status 1. See Shutdown under Design for what a stop writes and what it
can lose.
seconds to stop and then exits with status 0. A stop that is still running
after 9 seconds exits with status 1 instead. See Shutdown under Design for
what a stop writes and what it can lose.
## Design
### Parts
The parts are built in two steps. The `fx` library, which wires a Go program's
parts together, builds the database, the routing table, the streamer and the
HTTP server. `RouteWatch.Run` in `internal/routewatch/app.go` builds the
handlers, the WHOIS fetcher, the blocklists and the database maintainer, and
starts every part. The parts:
The parts are built in two steps:
- The `fx` library, which wires a Go program's parts together, builds these:
- the database
- the routing table in memory
- the streamer
- the HTTP server
- `RouteWatch.Run` in `internal/routewatch/app.go` builds the other parts and
starts them all.
The parts:
- The streamer connects to RIS Live, reads the JSON stream and parses the BGP
messages. It gives each message to the handlers that want it, through one
@@ -593,8 +629,8 @@ starts every part. The parts:
address.
- The database maintainer checkpoints the database every 5 seconds: it folds the
write-ahead log, where SQLite first writes changes, into the database file. It
reclaims free space every 10 minutes and refreshes the query statistics every
hour.
reclaims free space every 10 minutes. Every hour it refreshes the statistics
SQLite uses to plan its queries.
- The HTTP server serves the pages and the API. Every route it shows comes from
the routing table in memory. AS names, WHOIS details and first-seen times come
from the database. The AS name search reads the AS list built into RouteWatch.
@@ -623,8 +659,10 @@ The prefix handler applies each update as it handles it:
The address lookup finds the most specific prefix that holds the address. It
looks the address up at each mask length, longest first: at most 25 lookups for
IPv4 and 113 for IPv6. Prefixes shorter than `/8` for IPv4 or `/16` for IPv6,
such as a default route, are not used.
IPv4 and 113 for IPv6. Prefixes shorter than `/8` for IPv4 or `/16` for IPv6 are
not used. Such a prefix says only where a peer sends traffic that matches no
better route; it does not say who holds the address. One of them is the default
route, `0.0.0.0/0` or `::/0`, which matches every address.
The database's `routes` table has one row for each prefix and origin AS. Every
second the prefix handler writes the pairs that changed, at most 20,000 in one
@@ -693,8 +731,9 @@ On `SIGTERM` or `SIGINT` the daemon stops its parts in this order:
6. the HTTP server
Last, the daemon checkpoints and closes the database. It gives all this 8
seconds and then exits with status 0. A stop still not done after 9 seconds ends
with status 1. When RouteWatch stops on an error, it exits with status 1.
seconds and then exits with status 0. A stop that is still running after 9
seconds exits with status 1 instead. When RouteWatch stops on an error, it exits
with status 1.
What a stop can lose:
@@ -782,7 +821,8 @@ The `make` targets:
- `make fmt`: format the Go code and the markdown
- `make fmt-check`: check the formatting without writing
- `make check`: run the tests, the linter and the format check
- `make hooks`: install the git pre-commit hook
- `make hooks`: install the git hook that runs `script/precommit` before each
commit
- `make build`: build `bin/routewatch`
- `make run`: build the binary and run it with debug logging
- `make clean`: delete `bin/`
@@ -793,8 +833,9 @@ The `make` targets:
The tests and the linter run only in Docker, as the `test` and `lint` phases of
the `Dockerfile`. The image cannot be built unless both pass. Every
`docker build` in `script/` passes a new `CACHEBUST` value, so each run executes
every check. Go's build cache and the linter's cache are kept between builds.
`docker build` in `script/` passes a new value of the `CACHEBUST` build
argument, so each run executes every check. Go's build cache and the linter's
cache are kept between builds.
The test suite runs with `-short`, which skips `TestRouteWatchLiveFeed`. That
test streams the live feed for a few seconds. No `make` target runs it.
@@ -804,12 +845,13 @@ test streams the live feed for a few seconds. No `make` target runs it.
This repository adheres to the
[Scripts to Rule Them All](https://github.com/github/scripts-to-rule-them-all)
standard: the scripts in `script/` are the entrypoints of the development
workflow, and the `Makefile` targets call them. The scripts:
workflow. Every `make` target except `make build`, `make run` and `make clean`
calls one of them. The scripts:
- `script/bootstrap`: install the development dependencies:
- `git`, `make` and Go, when they are missing
- the pinned node and yarn
- prettier, from `yarn.lock`
- the pinned versions of node and yarn
- prettier, the markdown formatter, from `yarn.lock`
- the Go modules
- `script/setup`: make a fresh clone ready for development. It runs
`script/bootstrap`, then `script/install-precommit`.
@@ -830,8 +872,8 @@ workflow, and the `Makefile` targets call them. The scripts:
- `script/precommit`: the pre-commit gate. It runs `go mod tidy` and `go fmt`,
then `script/check`. `go mod tidy` must leave `go.mod` and `go.sum` unchanged;
`go fmt` writes.
- `script/install-precommit`: install the git pre-commit hook that runs
`script/precommit`.
- `script/install-precommit`: install the git hook that runs `script/precommit`
before each commit.
- `script/asupdate`: rebuild the AS list built into RouteWatch,
`pkg/asinfo/asdata.json.gz`, from the `as.csv` file of
[ipverse/as-metadata](https://github.com/ipverse/as-metadata). It needs the