Commit Graph
4 Commits
Author SHA1 Message Date
Ettore Di Giacinto db9a0a763a feat(distributed): carry an agent cancel on the worker's own tunnel
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>
2026-09-20 03:05:35 +00:00
Ettore Di Giacinto 06f58d0d88 feat(distributed): dispatch queued work as a claim queue
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>
2026-09-20 03:05:34 +00:00
Ettore Di Giacinto 2f3d5b2e74 feat(distributed): make MCP execution and discovery a selection
mcp.tools.execute and mcp.discovery were the only NATS subjects that
combined a queue group with a reply, and no carrier in this design
provides both. They never needed one: a queue group is a way of choosing
a subscriber, and choosing is a query.

The frontend now lists the approved, non-draining agent nodes, asks the
node_connections table in one joined statement which of those tunnels a
live replica holds, prefers one this replica holds so the call skips the
relay hop, and issues an ordinary control RPC on the path task 4 already
mounted. A peer-held tunnel is reached through the relay. That is a
choice a broker's hidden balancing could not make.

The selection reads presence and nothing else. It is filtered only on
node type and on the two statuses an operator controls, never on a health
verdict written on another clock, because refusing a worker that is
connected and answering is the same defect as picking one that is gone.
An empty fleet answers ErrNoAgentWorker, which is deliberately neither
ErrWorkerUnroutable nor anything cluster.IsWorkerAnswer accepts: nothing
was asked of any worker, so no reap guard may act on it.

A reply carrying an Error is the worker's own answer and is returned
unchanged; it is never offered to a second worker, which would turn "this
MCP server rejected your arguments" into "the fleet is broken" and could
run a tool twice. A call that never reached a worker is retried against a
different pick, at most three times, and whatever error is finally
returned is returned unwrapped so its identity survives the loop.

MCP prompts and resources now answer 501 in distributed mode instead of
an empty 200. They are served only from sessions the frontend holds, and
in distributed mode it holds none. That gap predates the removal of the
bus and is not closed by it; this only stops it being silent.

Agent workers keep every other subject, including nodes.<id>.backend.stop.
Their minted JWT loses the two MCP subjects and keeps a non-empty allow
list, because NATS reads an empty one as no restriction at all.

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 12571d22d9 feat(distributed): give agent workers a tunnel of their own
Phase 2 gated agent nodes out of tunnel credentials at the mint site.
That was right while nothing dialled into an agent worker: a credential
would have replaced nothing, and the gate was structural rather than a
second check that could drift. It is wrong now that the frontend needs to
reach an agent worker by RPC.

attachTunnelToken mints for backend and agent nodes and CLEARS for
anything else, through one tunnelEligible predicate rather than two
conditions that can be widened separately. ConnectHandler still never
reads NodeType, so an empty hash is still what refuses an ineligible
node.

An agent worker now starts a loopback control server behind the same
bearer check a backend worker uses, and holds one tunnel whose only
stream tag is http: it runs no backend processes, so the grpc tag has
nothing to route to and is not offered. Its MCP tool, MCP discovery and
backend.stop verbs are served from ONE implementation reached by both the
bus and the tunnel, so a frontend cannot get different bytes depending on
which carrier delivered.

The tunnel is an ADDITION. --nats-url is still required, and agent jobs,
MCP execution, MCP CI jobs and nodes.<id>.backend.stop all still travel
on the bus.

Absence semantics are unchanged. An agent node now has a real
node_connections row whose departure ages past the grace, so the node
type check in HealthMonitor.tunnelDeparted stopped being an optimisation
and became the rule; its comment says so, and the spec that pins it is
shown red under a mutation that deletes the check. The scheduler needed
no change: every placement query already filters node_type = backend, so
an agent node never reaches nodeMayTakeWork.

Shared rules moved to one site each. The request bounds, the POST-only
check and the unknown-path 404 live in workerctl and are called by both
worker packages; the bearer check that guards every extra route is one
function in core/services/nodes used by both server constructors.
workerctl.AllPaths splits into BackendPaths and AgentPaths, with AllPaths
as their deduped union, because a backend worker does not mount the agent
verbs and asserting otherwise would fail a correct worker.

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