agent.<name>.cancel was the last family on a message bus, and the only
reason an agent worker dialled one. Its subscriber is the worker running
the execution, and a worker has no database, so the family could not move
to the PostgreSQL fan-out carrier: a cancel published there would reach no
worker while reporting that it had been sent.
It is a control verb now. An agent worker mounts workerctl.PathAgentCancel
on the loopback control plane behind its tunnel and applies the cancel to
the same registry the executor registers a run on. The frontend issues it
through nodes.AgentControlClient.CancelAgentRun.
That call is a FAN-OUT and not a pick, because nothing records which worker
holds a given execution: the claim row names the claiming replica, and it
is deleted when the run ends. Every agent worker a live replica can reach
is asked over its own tunnel, relayed by the peer mesh when a peer holds
it, and each worker answers only for itself.
The answers stay apart, which is why this family was held back. A cancel a
worker made is nil. A cancel some worker could not be asked is
ErrAgentCancelUndelivered, which is neither a refusal nor a missing run. A
cancel every reachable worker declined to own is ErrAgentRunNotOnAnyWorker.
A deployment with no agent worker is ErrNoAgentWorker. Neither new sentinel
wraps ErrWorkerUnroutable and neither is a worker answer, so nothing is
reaped, demoted or evicted because of a cancel.
A worker in the ABSENT CONNECTION condition, one whose tunnel was lost
inside the reconnect grace, counts as undelivered. It is not retried in the
call and not queued: a retry would spend a budget the caller did not
choose, and a queue would need durable state whose only consumer is a run
whose control stream went with the tunnel. A worker whose departure has
outlived the grace is the one routing fact a caller may act on and is
excluded, or a single retired agent node would make every cancel
undelivered for ever.
The fan-out reads a different node set from the pick. A draining worker
takes no new work but is still finishing what it holds, so it is offered
the cancel; a pending one is refused by the tunnel route on every dial and
is not.
With that, nothing in LocalAI connects to NATS. The agent worker's dial,
its credential ladder and its refresh loop are gone, and so is the
frontend's cancel carrier. LOCALAI_NATS_URL is accepted and ignored
everywhere, and distributed mode no longer requires it.
Assisted-by: Claude Opus 5 [claude-code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
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>
The three NATS queue groups jobs.new, jobs.mcp-ci.new and agent.execute are
gone. Dispatching work is now a row in a work_claims table, taken by one
frontend replica with SELECT ... FOR UPDATE SKIP LOCKED and driven on an agent
worker as a streaming control RPC over that worker's tunnel. Exactly-one
delivery among competing consumers is a database problem, not a broker feature.
An agent worker has no database, so it never claims; it executes what the
claiming replica hands it.
A claim must not outlive the replica that took it. The reap releases a claim
whose owner is no longer a live replica in the instances table, on the database
clock, and never asks how long the claim has been held. A job that legitimately
runs for an hour on a heartbeating replica is left alone, while a claim whose
owner stopped heartbeating becomes claimable again within one liveness window.
A replica with no advertised address has no instances row at all, so it refuses
to claim rather than have its work reaped out from under it mid-run.
The settle rule is stated once, in settleClaim, and every exit path calls it. A
transport failure releases the claim and never completes or discards it; only a
decoded reply line completes it. That line is deliberately not
cluster.IsWorkerAnswer, which accepts the stream refusals a worker's tunnel
writes before any request body reaches its control server: completing on those
would discard work that never ran.
The terminal line is persisted before the claim is completed, so a store that
refuses leaves the claim standing rather than leaving the job running for ever.
That is the dropped-result defect fixed structurally rather than by retry.
This also surfaces a pre-existing gap rather than causing one: no worker has
ever served plain task jobs, and publishing them into an empty queue group left
them running with no trace. Such a claim is now failed with a reason.
Removes QueueWorkers, --agent-subject and --agent-queue, and narrows an agent
worker's minted JWT by agent.execute and jobs.mcp-ci.new.
Assisted-by: Claude Opus 5 [claude-code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Ettore Di Giacinto