Commit Graph

3 Commits

Author SHA1 Message Date
Joseph Doherty d32d89c340 fix(drivers): stop silently discarding driver config edits (§8.3, #516)
Five drivers ignored the config handed to them on reinitialize, serving the
options their constructor captured — and the deployment sealed green anyway.
Fixed on both halves, as chosen.

Seam (load-bearing): DriverSpawnPlanner routes a changed DriverConfig to
ToStop + ToSpawn instead of an in-place delta, making the factory the single
parse authority. This REVERSES the deliberate decision documented at
DriverSpawnPlan.cs:49-50 ("a pure DriverConfig change stays an in-place delta
— no reconnect"). That reasoning was correct about the resilience pipeline and
wrong about the driver. The accepted price is a reconnect per config edit.

Per-driver, and this split was not anticipated:
- Re-parse in place — Modbus, AbLegacy, OpcUaClient. ParseOptions extracted
  from each factory, called from InitializeAsync behind a HasConfigBody guard
  so "{}" still keeps the constructor options.
- Respawn-only, deliberately NOT re-parsed — Sql and FOCAS. Each builds more
  than options from config (Sql's dialect + resolved connection string,
  FOCAS's client-factory backend, both injected at construction), so adopting
  new options alone would run a NEW tag set against an OLD connection. Half a
  re-parse is worse than none. SqlDriver's doc-comment asserted the opposite
  premise — "config parsing belongs to the factory, which builds a fresh
  instance" — which was false when written and is true only now.

Two green seals removed from ApplyChildDelta: it overwrote the cached Spec
synchronously BEFORE the child dequeued the message, so the host believed the
new config was live and the next reconcile computed no delta, sealing the
drift permanently; and it Tell'd with no Receive<ApplyResult> registered, so a
failed reinit — including Galaxy's deliberate NotSupportedException —
dead-lettered.

Exposed (not created) by the change: a factory throw is a CONFIG error, and
SpawnChild catches it and silently substitutes a stub. Only a brand-new driver
could reach that before; an ordinary config edit can now. Raised Warning ->
Error with an actionable message. It still does not fail the deployment —
doing so would let one malformed driver block a fleet deploy, so that is a
follow-up rather than a drive-by.

Tests: every pre-existing reinit test in these suites passes "{}", the exact
input a guarded re-parser treats as "keep constructor options" — blind to this
defect by construction. New tests pass CHANGED json; the Modbus one was
verified falsifiable by deleting the re-parse (goes red). Two tests asserted
the old behaviour and were rewritten, including the positive control in
DriverHostActorUnreadableArtifactTests, whose observable moved from
UnsubscribeAsync to ShutdownAsync now that teardown happens by stopping the
child rather than emptying its desired set.

Remaining full-suite failures are pre-existing and environmental, verified
identical on the pre-change tree: Host.IntegrationTests (3) and
Driver.AbLegacy.IntegrationTests (4, docker fixture-gated).
2026-07-27 19:32:46 -04:00
Joseph Doherty ef41a43102 fix(drivers): fail the apply when the artifact could not be read (#486)
ApplyAndAck advanced _currentRevision and recorded NodeDeploymentState=Applied
immediately after ReconcileDrivers, which returns null when the artifact could
not be read. So a node that applied NOTHING reported success, claimed a
revision whose configuration it never applied, and — because
HandleDispatchFromSteady short-circuits on a revision match — could never be
healed by re-dispatching that revision. Only a later, different revision
recovered it.

Now a null blob fails the apply: the revision is left where it was,
NodeDeploymentState records Failed with the reason, and the coordinator gets a
Failed ACK. Leaving the revision alone is what makes the retry actually land
instead of being waved through.

This is about telling the truth, not about tearing anything down — the node
keeps serving its last-known-good address space, drivers and subscriptions
throughout (#485).

Tests, RED-first (both verified failing with "should be Failed but was
Applied"): the ACK/revision assertion, plus the one that matters — after a
failed apply, re-dispatching the SAME revision now genuinely applies. Its
recovered artifact adds a second driver precisely so a short-circuited ACK
(which has no side effects) cannot satisfy it.

Four existing tests changed, and both changes are deliberate:

- DriverHostActorTests.SeedDeployment never set ArtifactBlob at all. Its three
  consumers are about the apply/ACK/state machine, not the artifact, and now
  need a genuine apply — so the helper seeds a well-formed artifact declaring
  no drivers. That is what the composer emits for an empty configuration, and
  is precisely what "bytes we could not read" is NOT.
- EmptyArtifact_IsNotCached asserted "the apply still succeeds — an empty
  artifact is a legitimate no-op deployment". That premise is the bug. Flipped
  to Failed; the test's actual subject (nothing is cached) is untouched and now
  holds for two independent reasons.

Closes #486

Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
2026-07-21 03:22:40 -04:00
Joseph Doherty b0c031f09f fix(drivers): don't tear down field I/O when a deploy's artifact reads back empty (#485)
The driver-side half of the same mistake the address-space fix corrected.
ReconcileDrivers and PushDesiredSubscriptionsFromArtifact both read the
artifact as `...FirstOrDefault() ?? Array.Empty<byte>()`. Their THROW paths
already returned early, but empty bytes flowed onwards as a real answer: zero
driver specs, so DriverSpawnPlanner planned every running child for StopChild,
and then an empty desired set dropped each surviving driver's live
subscription handle. A node lost its entire field I/O and still ACKed Applied.

Same rule as the address space: no bytes is no answer, not "a configuration
with no drivers". Nothing legitimate produces a zero-length blob — deleting
the last driver still deploys a JSON document with empty arrays. Both sites
now skip and keep what is running. The two guards are independent because
PushDesiredSubscriptions does its OWN ConfigDb read, so the row can go missing
between them.

Also corrects the ReconcileDrivers doc comment, which claimed an empty blob
made it "effectively a no-op" — with children running it was the opposite.

Tests: DriverHostActorUnreadableArtifactTests, RED-first (verified failing —
after the empty dispatch the driver list was empty). A zero-length ArtifactBlob
reproduces byte-for-byte what the missing-row case delivers, so the race does
not have to be constructed.

Two controls, both load-bearing:
- a READABLE driverless artifact still stops the driver, so the guard keys on
  "the read gave us nothing", not on "fewer drivers than before";
- dropping a driver's LAST TAG still clears its subscription. This one was
  added after the absence assertion was caught passing on a race: the
  unsubscribe is an async self-tell, so with the second guard deleted the test
  still went green. The control observes that same unsubscribe arriving well
  inside the settle window, which is what makes the absence meaningful — with
  the guard deleted the suite now correctly goes RED.

SubscribableStubDriver gains an UnsubscribeCount for that observation.

Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
2026-07-21 02:40:14 -04:00