Closes the observer half of #162 that was flagged as "persisted as 0 today"
in PR #105. The Admin /hosts column refresh + FleetStatusHub SignalR push
+ red-badge visual still belong to the visual-compliance pass.
Core.Resilience:
- DriverResilienceStatusTracker gains RecordCallStart + RecordCallComplete
+ CurrentInFlight field on the snapshot record. Concurrent-safe via the
same ConcurrentDictionary.AddOrUpdate pattern as the other recorder methods.
Clamps to zero on over-decrement so a stray Complete-without-Start can't
drive the counter negative.
- CapabilityInvoker gains an optional statusTracker ctor parameter. When
wired, every ExecuteAsync / ExecuteAsync(void) wraps the pipeline call
in try / finally that records start/complete — so the counter advances
cleanly whether the call succeeds, cancels, or throws. Null tracker keeps
the pre-Phase-6.1 Stream E.3 behaviour exactly.
Server.Hosting:
- ResilienceStatusPublisherHostedService persists CurrentInFlight as the
DriverInstanceResilienceStatus.CurrentBulkheadDepth column (was 0 before
this PR). One-line fix on both the insert + update branches.
The in-flight counter is a pragmatic proxy for Polly's internal bulkhead
depth — a future PR wiring Polly telemetry would replace it with the real
value. The shape of the column + the publisher + the Admin /hosts query
doesn't change, so the follow-up is invisible to consumers.
Tests (8 new InFlightCounterTests, all pass):
- Start+Complete nets to zero.
- Nested starts sum; Complete decrements.
- Complete-without-Start clamps to zero.
- Different hosts track independently.
- Concurrent starts (500 parallel) don't lose count.
- CapabilityInvoker observed-mid-call depth == 1 during a pending call.
- CapabilityInvoker exception path still decrements (try/finally).
- CapabilityInvoker without tracker doesn't throw.
Full solution dotnet test: 1243 passing (was 1235, +8). Pre-existing
Client.CLI Subscribe flake unchanged.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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