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fix(distributed): make admin backend installs resilient and observable#9958

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mudler merged 29 commits into
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fix/distributed-install-timeout-and-progress
May 23, 2026
Merged

fix(distributed): make admin backend installs resilient and observable#9958
mudler merged 29 commits into
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fix/distributed-install-timeout-and-progress

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Summary

Two related fixes for distributed-mode admin backend installs, motivated by a real cluster install of vllm-development across slow nodes (Jetson, dgx-spark, nvidia-thor) that surfaced nats: timeout errors with no visibility into worker state.

Phase 1 - timeout + state-machine resilience (11 commits)

  • LOCALAI_NATS_BACKEND_INSTALL_TIMEOUT / LOCALAI_NATS_BACKEND_UPGRADE_TIMEOUT env vars (default 15m, previously hardcoded 3m for install — easily blown by multi-GB OCI image pulls on Wi-Fi).
  • New galleryop.ErrWorkerStillInstalling sentinel: when the NATS round-trip times out but the worker is still pulling the image in the background, the master no longer reports a hard failure. Per-node status becomes running_on_worker, the pending queue row stays alive (without bumping Attempts so it can't trip the dead-letter cap), and NextRetryAt is pushed by the install timeout.
  • galleryop.backendHandler surfaces this as a yellow Processed: true OpStatus with a worker still installing in background message instead of a red error.
  • Phase 1b: DistributedBackendManager.ListBackends proactively clears install rows whose intent is now satisfied by backend.list confirmation, so the operator UI updates immediately instead of waiting up to 15m for the next reconciler tick.

Phase 2 - streaming progress over NATS (8 commits)

  • New transient subject nodes.<nodeID>.backend.install.<opID>.progress. Worker publishes debounced (~250ms) BackendInstallProgressEvent values; master subscribes for the duration of the install request and forwards each event into galleryop.ProgressCallback → existing OpStatus.UpdateStatus, so the admin UI / SSE polling gets per-byte progress for distributed installs the same way local-mode does — no UI changes needed.
  • Backward compatible: workers on pre-2026-05-22 code don't publish on the new subject; new masters tolerate silence (install reply remains source of truth for terminal state). Reconciler retries skip subscription entirely.

Test plan

  • CI green on the existing core/services/{nodes,messaging,galleryop,worker,config} suites (testcontainers Postgres included). 208 specs total, all pass locally (~108s for nodes).
  • Build a worker + master with these changes, install a large OCI-backed backend (e.g. cpu-vllm) on a slow link. Confirm:
    • The admin UI shows real-time per-byte progress instead of stalling at "still installing".
    • If a single install does exceed LOCALAI_NATS_BACKEND_INSTALL_TIMEOUT, the op surfaces as yellow worker still installing in background instead of red.
    • Once the worker finishes and the next ListBackends poll observes the backend installed, the pending queue row clears and the UI flips to terminal success without waiting for the reconciler.
  • Verify mixed-version cluster (old worker + new master): silent install still completes; no spurious errors.
  • LOCALAI_NATS_BACKEND_INSTALL_TIMEOUT=5s end-to-end smoke (force the soft-failure path) - the op should reach Processed: true with the in-progress message within 5s and clear on the next ListBackends.

Out of scope

  • Phase 3 (compatibility-aware fanout): filter incompatible variants per-node BEFORE NATS install so an arm64 node doesn't get sent a cpu-vllm request that fails with no child with platform linux/arm64 in index. Independent fix, separate PR.
  • Phase 4 (React UI): per-node breakdown rows, phase chips, install retry-per-node button. Depends on Phase 2 data flowing through. Separate PR.
  • Phase 2 polish (followups noted inline as code comments): progress-event ordering at the master is best-effort (one goroutine per event). A future Seq uint64 field on the wire event would let the bridge drop stale-by-seq. Also, a late goroutine could briefly overwrite the terminal OpStatus with an older percentage - bounded and self-correcting.
  • UpgradeBackend progress streaming: BackendUpgradeRequest has no OpID field; upgrade is the rarer admin path. Will be picked up alongside any future upgrade UX work.

Notes

  • Every commit is signed off with the DCO trailer; no Co-Authored-By trailers.
  • Docs added in docs/content/features/distributed-mode.md covering both env vars and the new progress subject.

Assisted-by: Claude:opus-4.7 [Claude Code]

mudler added 29 commits May 22, 2026 19:39
…outs

Adds BackendInstallTimeout and BackendUpgradeTimeout to DistributedConfig
with 15m defaults, following the existing MCPToolTimeout / WorkerWaitTimeout
pattern. These will replace the hardcoded literals in RemoteUnloaderAdapter
so admin-driven backend installs across the cluster survive long OCI image
pulls that previously timed out at 3m.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Re-aligns the Validate() negative-duration map and the Default* const
block so the new BackendInstall/UpgradeTimeout entries do not leave
the surrounding columns mis-padded.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
…TIMEOUT

Parses the two new env vars on the run CLI and threads them through the
existing AppOption builder so DistributedConfig picks them up. Invalid
duration strings now fail loudly at startup rather than silently falling
back to the default.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
…loaderAdapter

Removes the hardcoded 3m / 15m literals from RemoteUnloaderAdapter and
threads in DistributedConfig.BackendInstallTimeoutOrDefault() and
BackendUpgradeTimeoutOrDefault() at construction. Install now defaults
to 15m (was 3m); cold OCI image pulls on Jetson Wi-Fi routinely blew
past the old ceiling. Scripted messaging client captures the timeout
so tests can assert the configured value actually reaches the NATS
request.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
When the NATS request-reply for backend.install (or .upgrade) times out
the worker is almost always still pulling the OCI image. Wrap the timeout
in a typed sentinel so the manager above can distinguish "worker hung"
from "worker still working" and leave the pending_backend_ops row in
place for the reconciler to confirm via backend.list.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
…lure

When a worker times out replying to backend.install but the install is
still running on the worker, enqueueAndDrainBackendOp now reports a
running_on_worker status and pushes NextRetryAt out by the install
timeout so the reconciler does not immediately re-fire another install
while the worker is still pulling the image. The pending_backend_ops
row stays in place for the next reconciler pass to confirm via
backend.list.

InstallBackend wraps the result in galleryop.ErrWorkerStillInstalling
so callers can branch (galleryop renders yellow in-progress instead of
red error). UpgradeBackend uses the same wrap.

Adds RemoteUnloaderAdapter.InstallTimeout() so the manager can push
NextRetryAt by the configured timeout without reaching into a private
field, and NodeRegistry.RecordPendingBackendOpInFlight as the soft
cousin of RecordPendingBackendOpFailure.

Also includes incidental gofmt-driven struct-field alignment in
registry.go on lines unrelated to the change (touched files are
re-formatted to canonical form per project policy).

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
An in-flight timeout (worker still pulling the OCI image) is not a
failed attempt, it's a delayed one. Incrementing Attempts let
genuinely-progressing slow installs (e.g. 30 GB CUDA images on Wi-Fi)
trip the reconciler's maxPendingBackendOpAttempts cap and dead-letter
the queue row while the worker was still legitimately working.

RecordPendingBackendOpInFlight now only updates LastError and NextRetryAt.
Also documents "running_on_worker" in the NodeOpStatus.Status enum
comment so Task 6 implementers see the full surface.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
When the distributed backend manager returns an error that wraps
ErrWorkerStillInstalling, backendHandler now completes the op with a
"still installing in background" message rather than marking it as a
red failure. Admin UI sees a yellow in-progress state; reconciler
confirms completion on its next pass.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Wires Task 1-6 end-to-end so any seam mismatch surfaces in CI rather
than during a real cluster install. NATS times out, the queue row
stays alive with running_on_worker status, the worker eventually
reports the backend installed via backend.list, the manager surfaces
it via ListBackends.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
…PGRADE_TIMEOUT

Add the two new operator-tunable env vars to the Frontend Configuration
table in the distributed-mode docs. Explains the 15m default, when to
raise it (slow links pulling multi-GB OCI images), and the new
"still installing in background" admin-UI state when the round-trip
times out but the worker is still working.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
DistributedBackendManager.ListBackends now proactively clears
pending_backend_ops install rows whose (nodeID, backend) is reported
installed by backend.list. Operator UI updates immediately instead of
waiting up to installTimeout (default 15m) for the next reconciler
tick after NextRetryAt.

Only install rows are cleared; upgrade and delete intents are not
satisfied by presence in backend.list and continue to drain through
their normal reconciler paths.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
New NATS subject nodes.<nodeID>.backend.install.<opID>.progress lets the
worker publish transient progress events (file, current/total bytes,
percentage, phase) while a long-running install pulls its OCI image.
BackendInstallRequest gains an optional OpID field so the worker knows
which subject to publish on.

Transient pub/sub (not JetStream): the install reply remains ground
truth for success/failure; dropped progress events are tolerable.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Per project convention (no em-dashes anywhere). Comment substance is
unchanged.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
When BackendInstallRequest.OpID is set, the worker's backend.install
handler wires a debounced publisher (250ms window) into the gallery
download callback. Each tick becomes a BackendInstallProgressEvent on
nodes.<nodeID>.backend.install.<opID>.progress; the publisher always
emits a final event on Flush so the UI sees the terminal percentage.

Old masters that do not set OpID continue to run silent installs: no
behavior change for them. Lock ordering: the publisher releases its
mutex before calling messaging.Publish so a slow network never stalls
the install loop.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
InstallBackend gains opID + onProgress parameters. When both are set,
the adapter subscribes to nodes.<nodeID>.backend.install.<opID>.progress
BEFORE publishing the install request, decodes each message into the
caller's onProgress callback in a goroutine (so a slow callback never
stalls the NATS reader thread), and unsubscribes after RequestJSON
returns.

When onProgress is nil OR opID is empty (the reconciler retry path),
subscription is skipped entirely - silent installs cost nothing extra.

Subscribe failure is logged at Warn and the install proceeds without
progress streaming; the NATS round-trip still owns terminal status.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
…Status

DistributedBackendManager.InstallBackend now passes the gallery op ID
and a progress bridge into the adapter call. Each
BackendInstallProgressEvent from the worker becomes a
galleryop.ProgressCallback tick - which the existing backendHandler
already turns into OpStatus.UpdateStatus, so the admin UI/SSE polling
sees per-byte progress for distributed installs without any UI-side
change.

UpgradeBackend is intentionally left silent for now: its wire request
(BackendUpgradeRequest) does not carry OpID, and rolling-update
fallback is the rarer path. Will be picked up in a follow-up if the
worker upgrade path also gets a progress channel.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
A worker on pre-Phase-2 code never publishes progress events. The new
master subscribes optimistically; this spec pins that a silent worker
still produces a green install with no progressCb ticks. The install
reply is the source of truth for terminal state; the progress stream
is a best-effort UX enrichment.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Note the new nodes.<nodeID>.backend.install.<opID>.progress subject and
the silent-worker compatibility behavior so operators know to expect
real-time progress and what happens on a mixed-version cluster.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
…ackend

Document near the goroutine dispatch why ordering at the consumer is
best-effort, why it rarely matters in practice (worker debounce >>
goroutine jitter), and what a future hardening pass would look like
(Seq field + stale-by-seq drop). Stops the next reader from accidentally
"fixing" the goroutine pool away.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
…down

Adds the data model the UI needs to render an expandable per-node
breakdown of a fanned-out backend install. NodeProgress carries node
identity (ID + name), per-node status (queued / running_on_worker /
success / error / downloading), the current file + bytes + percentage
from the Phase 2 progress stream, and any per-node error.

OpStatus.Nodes is the slice the /api/operations handler will surface
in a follow-up.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
GalleryService.UpdateNodeProgress(opID, nodeID, np) merges a NodeProgress
into OpStatus.Nodes (keyed by NodeID, no duplicates) and mirrors the
latest tick into the aggregate Progress / FileName /
DownloadedFileSize / TotalFileSize fields so the legacy single-bar
OperationsBar view keeps working unchanged alongside the new per-node
breakdown.

Concurrent-safe via the existing g.Mutex.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
…-out

DistributedBackendManager now accepts a nodeProgressSink and feeds it
two streams:

1. enqueueAndDrainBackendOp emits a per-node terminal entry on each
   status it appends to BackendOpResult (queued, success, error,
   running_on_worker). The opID is threaded through the function so
   the sink gets the right gallery op identity.

2. The install apply closure fans each BackendInstallProgressEvent
   into the sink as a downloading entry, alongside the legacy
   progressCb path so the aggregate single-bar view stays correct.

Production wiring passes the GalleryService (which implements
UpdateNodeProgress via Task 2) as the sink. Single-node tests pass
nil. DeleteBackend and UpgradeBackend pass an empty opID so the
sink path no-ops for ops that aren't gallery-tracked the same way
as Install.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
When an operation's OpStatus has Nodes entries (populated by the
Phase 4 progress sink wiring), surface them as a "nodes" array on the
/api/operations response, sorted by node_name for stable rendering.

Backward compatible: legacy clients ignore the field; ops without any
node entries (single-node mode, model installs) omit the array entirely
thanks to the empty-slice guard.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
When an install op fans out to more than one worker, the operations
bar now shows a "N nodes" chevron that expands into a per-node list.
Each row carries the node's status (color-coded pill), the current
file being downloaded, byte counts, percentage, and a thin per-node
progress bar. Yellow "Worker busy" pill marks running_on_worker
status with a tooltip explaining the NATS round-trip timed out but
the worker is still installing in the background.

Backward compatible: ops without a nodes field (legacy or single-node
mode) render as before. State for expand/collapse is local to the
component, keyed by jobID/id - reload starts collapsed.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Adds a short subsection covering the expandable "N nodes" chevron in
the OperationsBar admin UI, the meaning of each status pill, and
how it relates to the /api/operations nodes array.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Real-world bug surfaced by the Phase 4 multi-worker smoke test: the
nodes[] array in /api/operations flickered between a single node at a
time on a 2-worker install. Root cause: the Phase 2 progress bridge
also calls the legacy progressCb -> UpdateStatus(&OpStatus{...}) on
every tick. UpdateStatus then overwrote the entire status pointer,
wiping the Nodes slice that UpdateNodeProgress had just merged in.

Fix: in UpdateStatus, if the incoming op has an empty Nodes slice,
carry forward the previous status's Nodes before storing. Callers
that explicitly populate Nodes still win (their slice replaces the
prior one, no merge across the two code paths).

Two regression specs added pinning both directions of the contract.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Trim the new install/upgrade timeout rows and the install-progress
sections to focus on what the operator sees and tunes. Drops:

- the NATS subject names and pub/sub mechanics
- "round-trip" / reconciler / backend.list jargon
- /api/operations polling cadence
- "pre-2026-05-22" version references

Reframes the breakdown text around the admin UI (Operations Bar,
chevron, status pills, "Worker busy" tooltip). Implementation context
lives in the agent notes and code comments.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
…ants

The negative-duration check map was a wall of literal kebab-case
strings that had to stay in sync with the kong-derived CLI flag names
manually. Move them to a Flag* const block alongside the existing
Default* block so a rename of either the Go field or the CLI naming
convention forces a compile error rather than silent drift.

Sole consumer today is Validate; the constants are exported so future
operator-facing surfaces (e.g. error messages on other validation
paths) can reference them by name instead of repeating the literals.

Tests pin both the literal values (so a future "let's just rename
this" doesn't accidentally regress the CLI flag) and the negative-
duration error message for the new BackendInstall / BackendUpgrade
fields.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Sweep for the same literal-string-as-identifier pattern called out on
the Validate flag names: the per-node install status enum
("queued" | "downloading" | "running_on_worker" | "success" | "error")
appeared as raw literals across managers_distributed.go (10+ sites,
including 3 separate `n.Status == "running_on_worker"` checks),
operation.go, and the test suite. Same shape for the Phase enum
("resolving" | "downloading" | "extracting" | "starting") in the
worker-side progress publisher.

Promote both to exported const blocks:

- galleryop.NodeStatus{Queued,Downloading,RunningOnWorker,Success,Error}
  shared between galleryop.NodeProgress.Status (the wire field) and
  nodes.NodeOpStatus.Status (the in-process per-node summary)
- messaging.Phase{Resolving,Downloading,Extracting,Starting}
  shared between the worker publisher and any future consumer that
  needs to switch on phase

Tests pin both the literal values (so a future "let's just rename" doesn't
silently change the JSON wire) and use the constants in setup (so the
producer side stays drift-protected). Wire-format assertions on the
/api/operations JSON output keep their literals deliberately, so the
constant value can never silently diverge from what the UI receives.

Out of scope for this PR (separate cleanup): the finetune and
quantization job-status enums have the same anti-pattern with 14+
literal sites each, but predate this PR's work.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
@mudler mudler merged commit a0f3e26 into master May 23, 2026
57 of 58 checks passed
@mudler mudler deleted the fix/distributed-install-timeout-and-progress branch May 23, 2026 10:35
@localai-bot localai-bot added the bug Something isn't working label May 24, 2026
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