Commit Graph
6 Commits
Author SHA1 Message Date
Ettore Di Giacinto 016686a3db chore(distributed): take the nats-io modules out of the build
Distributed mode has not dialled a message broker since the control plane
moved onto the workers' own outward tunnels and every fan-out family moved
onto PostgreSQL LISTEN/NOTIFY. What was left was the dependency itself, and
the code that existed only to feed it.

Dropped from go.mod: nats-io/jwt/v2, nats-io/nats.go, nats-io/nkeys,
nats-io/nuid and testcontainers-go/modules/nats, along with the fourteen
indirect requires that only the NATS testcontainer pulled in. go.sum carries
no nats line either, so the removal is not the partial kind where the require
goes and the checksum stays.

Deleted with them: pkg/natsauth in full, the broker client's remaining
options and TLS files, the per-node JWT minting on both the register and the
approve path, and the natsauth.Config parameter threaded through the node
routes. The credential manager is renamed and stripped rather than deleted,
because it still holds the tunnel token that every re-registration rotates.

The bus flags stay accepted and ignored, and are now hidden, on every command
that had them, so an existing unit file, compose file or Helm values file
still starts on the day of the upgrade. What is not kept is the validation
that REQUIRED one: a distributed frontend started with no bus URL is no
longer fatal. The TLS paths lose type:"existingfile" deliberately, so a
certificate deleted along with the broker cannot fail a startup.

One operator-visible behaviour change: --nats-require-auth no longer makes an
agent worker wait through admin approval. Ask for that wait with
--distributed-require-auth, which already implied it. It is documented in the
migration section and pinned from both sides.

A deployment now needs PostgreSQL and the frontends' own HTTP listener, and
nothing else.

coverage-baseline.txt moves from 54.2 to 62.0.

Assisted-by: Claude Opus 5 [claude-code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
2026-09-20 03:05:35 +00:00
Ettore Di Giacinto be14db21e2 feat(distributed): move the last nine fan-out families onto PostgreSQL
Gallery progress and cancel, the operation cache's start and end, the model
and backend cache invalidations, staging progress, and the prefix cache's
observations and invalidations now travel on the LISTEN/NOTIFY carrier. No
subject is published or subscribed on messaging.Client anywhere in the tree,
which is what makes retiring that package a deletion rather than a migration:

  $ grep -rn 'natsClient\.Publish\|nats\.Publish\|\.Nats\.Publish\|QueueSubscribe\|SubscribeReply\|\.Request(' \
      --include='*.go' core/ pkg/ | grep -v _test \
    | grep -v 'c\.Request()\|ctx\.Request()\|Request()\.Context' \
    | grep -v 'core/services/testutil/fakebus.go'
  core/services/messaging/client.go:168,170,172,227,234,236,250,252,254,268,269,287
  core/services/messaging/interfaces.go:21,22,23

Every remaining hit is inside core/services/messaging itself. The production
reads of the NATS client are now three, all of them the documented agent-worker
exception: Close on shutdown, the agent pool's publisher, and the agent-cancel
carrier passed to newFanoutBridges.

Prefix-cache observations publish like every other family rather than through a
method that refuses a message too large for a notification. The plan proposed
such a refusal on the reasoning that a long prompt makes a chain of thousands of
entries; ExtractChain caps a chain at Config.MaxDepth blocks, MaxDepth is a
constant with no operator knob, and the chain reaching Sync.Observe has one
source, the router's own extraction hook. A worst-case observation is a few
kilobytes against an 8000-byte cap, so the hot-path spill the refusal was
designed to avoid cannot occur, and shipping it would have added the programme's
only deliberate message drop to guard a condition that cannot arise. pgbus gains
FitsInline instead, a predicate that shares one size decision with Publish and
decides nothing, and core/application refuses at startup to wire a prefix cache
whose configured depth would put every observation over the cap.

The carrier choice is no longer stated at four sites. StagingTracker.SetPublisher
and SubscribeBroadcasts become one SetBroadcaster, so a tracker that publishes
where its peers are not listening cannot be spelled; prefixcache.Sync gains
SubscribeBroadcasts, which reads the carrier it publishes on; and the gallery
service and the operation cache are wired by methods on DistributedServices that
name no carrier at all, so the NATS client beside it cannot be handed over.
OpCache.SetMessagingClient and GalleryService.SetNATSClient are renamed to
SetBroadcaster so a missed call site fails to compile.

Two pre-existing defects that the two-real-carrier specs surfaced are fixed. A
progress tick published before a cancel and delivered after it cleared Cancelled
and left the operation reading as still running on that replica; mergeStatus now
drops a stale tick rather than merging it. GetStatus and GetAllStatus handed out
the stored OpStatus pointer while the broadcast subscribers mutated it in place,
so an /api/operations response could be marshalled mid-write; both now copy.

Assisted-by: Claude Opus 5 [claude-code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
2026-09-20 03:05:34 +00:00
Ettore Di Giacinto c97a524013 refactor(distributed): move job and agent fan-out onto the PostgreSQL carrier
Five of the six families whose subscriber is an open HTTP response rather
than a process-lifetime cache now travel on pgbus: jobs.<id>.progress,
jobs.<id>.result, jobs.<id>.cancel, agent.<name>.events.<user> and
responses.<id>.cancel. Both ends of each move together, so there is no
state where a publisher is on one carrier and its subscriber on the other.

agent.<name>.cancel does NOT move, and the plan was wrong about why. Its
only subscriber in the tree is the agent worker, which has no database and
so cannot join the PostgreSQL carrier at all. Publishing that cancel on
pgbus would have lost every cancel of a worker-run agent while returning
nil, which reports a cancel that reached nobody as a cancel that was sent.
EventBridge now names its cancel carrier separately, a frontend replica
sets it to the carrier the worker reads, and it stays there until a cancel
rides the worker's tunnel like every other verb addressed to a worker.

The carrier drops at 256 rather than blocking, which is not safe on its own
for a result: a lost result has no successor message. It is not the only
path. The claiming replica persists the terminal line before it releases
the claim, and an open progress stream re-reads the job row once after
subscribing and then periodically, so a dropped terminal broadcast costs
promptness and never the answer.

Both per-request subscriptions close in a defer instead of on one return
path, and pgbus grows Subscribers() so the leak they would otherwise cause
can be asserted. It has no other symptom: only the first subscriber of a
channel issues a LISTEN, so a leaked filter just adds one closure per
notification for every stream the replica has ever served. Subscribe now
issues its LISTEN before it registers, which makes that count a readiness
signal rather than a figure to compare against itself.

Two rules that were stated at several sites and pinned at none are now one
each. The re-broadcaster is built beside the dispatcher and the bridge and
handed to the dispatch loop, so no line is left that can point it at a
carrier nobody subscribes to while every spec stays green. The set of
statuses a job never leaves is one exported set that the SSE bridge and the
store both read. The last hand-written subject filter in production code
became messaging.SubjectAgentEventsWildcard.

Assisted-by: Claude Opus 5 [claude-code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
2026-09-20 03:05:34 +00:00
Ettore Di Giacinto 5562cd7ad3 feat(distributed): keep the listener draining and let it come back
PostgreSQL holds undelivered notifications in a queue it shares with every
session on the server, and it kills a listener that stops draining. Two failure
modes follow, and both are silent: a carrier that blocked on a slow resolver
would lose its connection and with it every later broadcast, and a carrier that
reconnected without re-registering would be connected and deaf.

The receive and dispatch halves were already separate. What was missing is
everything around them. The listener path moves into listener.go and gains a
carrier-level Dropped() so a replica that is behind can be seen; the queue depth
and the spill retention become Config fields with exported defaults; the LISTEN
session gets an application_name so an operator can count listeners in
pg_stat_activity and a spec can drop exactly one of them; and OnReconnect fires
after the re-LISTEN, on a goroutine of its own, because a callback re-hydrates
from a database and must never run on the path whose only job is to drain.

That callback is reached through an optional interface assertion, so deleting
its invocation compiles and every adopter silently stops converging. The spec is
the only guard, and it is named in a comment at the site.

The slow consumer is proved through the transport rather than a seam: an ACCESS
EXCLUSIVE lock on bus_messages stalls the resolver's spill SELECT for exactly as
long as the spec holds it, and the listener is shown still draining and dropping
while it does. The dropped connection is a pg_terminate_backend matched on the
carrier's own application name.

Neither Dropped nor IsConnected is on messaging.Broadcaster, and a spec asserts
that over the interface type. Both are facts about a frontend; the conditions a
scheduler acts on are facts about a worker, and no consumer holding the
interface can read one as the other.

Assisted-by: Claude Opus 5 [claude-code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
2026-09-20 03:05:34 +00:00
Ettore Di Giacinto ecfa96875a fix(distributed): order LISTEN and UNLISTEN on one lock
Unsubscribe decided a channel had lost its last subscriber under one
lock and issued the UNLISTEN after releasing it. A Subscribe on the same
root could decide to LISTEN in that window, and the two reached the
connection in the wrong order: the root ended up not listened with a
live subscription on it. It does not heal, because the next Subscribe
sees the registration already there and never re-LISTENs, so the whole
root stays deaf on that replica until the connection drops.

The decision and the statement it implies now happen under one lock,
held across both, at both call sites. A second lock and not the
registration lock: issuing waits on the listener goroutine, delivery
takes the registration lock, and holding that across the wait deadlocks
the carrier.

The race is spec'd through a barrier seam rather than by racing
goroutines. The natural window is microseconds wide, and a spec that
waits for it to open passes by luck; the seam scripts the interleaving,
so the spec decides in both directions.

Resolving a spilled message moved off the listener. PostgreSQL keeps
undelivered notifications in a shared, fixed-size queue, so a listener
that stops draining it can block COMMIT for every publisher on the
server, not only this one. The listener now only drains; one resolver
goroutine reads the row back and dispatches, which also keeps a spilled
message and an inline one on the same subject in the order they were
published.

Three wiring lines that could be deleted with the suite staying green:
the sweeper's start is now pinned by a Config interval, and the two
lines that carry the bus into the deployment now refuse to boot when
either is missing. A subscription can also report what it dropped, so
the party that missed a message is the party that can see it.

Assisted-by: Claude Opus 5 [claude-code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
2026-09-20 03:05:34 +00:00
Ettore Di Giacinto 57cde52b8f feat(distributed): carry fan-out on PostgreSQL LISTEN/NOTIFY
Distributed mode needs an operator to run a NATS cluster. This adds the
carrier that replaces its fan-out half, so a deployment eventually needs
PostgreSQL and its own HTTP listener and nothing else.

pgbus holds one PostgreSQL session per replica, pinned for the life of
the process because LISTEN registrations belong to one backend session
and a pooled handle would lose them on the next checkout. Publishes go
out on the pool with pg_notify.

Subjects map onto a channel by their first token, from a closed set of
roots. A subject outside the set is refused at publish AND at subscribe
rather than mapped to a channel of its own: a channel name is capped at
63 bytes, and one LISTEN per job id would be unbounded. Refused rather
than dropped, because a subject that goes nowhere and reports nothing is
the class of defect this work exists to remove.

PostgreSQL refuses a notify payload of 8000 bytes or more, and several
subjects on this bus exceed that in normal operation: a job result
carries a whole LLM output, a gallery progress event carries one entry
per node. Those are written to a row and the notification carries the
id. What is measured against the cap is the ENCODED notification, not
the caller's payload, because the subject and the envelope travel too.

The filter grammar is not respelled here. Subscribe asks
messaging.ValidFilter and delivery asks messaging.SubjectMatches, which
makes this the first production caller of a matcher that had only test
doubles. New refuses a DSN that names a different database from the
pool: that pairing publishes successfully, delivers nothing, on every
replica, and reports no error anywhere.

Nothing publishes on it and nothing subscribes yet. The construction is
wired anyway, because the DSN has exactly one legitimate source and a
setting that decides whether any broadcast is delivered should not be
invented by whichever call site is migrated first.

Delivery is at-most-once, like NATS core. Nothing downstream may read a
message it did not receive as evidence about a node: a carrier that
cannot deliver is not a worker that is gone.

Assisted-by: Claude Opus 5 [claude-code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
2026-09-20 03:05:34 +00:00