Concurrency hazards, DI lifetime hygiene, and one verify-only confirmation
across 8 modules. Highlights:
Concurrency:
- CentralUI-030: SandboxConsoleCapture writes routed through WriteSynchronized
locking on the captured StringWriter — intra-script Task fan-out can no
longer corrupt the per-call buffer.
- Commons-021: ExternalCallResult.Response now backed by Lazy<dynamic?>
(ExecutionAndPublication) — no more benign double-parse race.
- CD-017: DeploymentManagerRepository.DeleteDeploymentRecordAsync now takes
an expected RowVersion and seeds entry.OriginalValues so EF emits
DELETE ... WHERE Id=@id AND RowVersion=@prior; stale RowVersion now
throws DbUpdateConcurrencyException instead of silent overwrite.
- Transport-009: AuditCorrelationContext.BundleImportId backed by
AsyncLocal<Guid?> so concurrent imports get per-logical-call isolation
(was a scoped instance shared via AuditService across runs).
DI / lifetime:
- AuditLog-003: All 3 AuditLog actor handlers switched to CreateAsyncScope
+ await using — async EF disposal no longer swallowed.
- AuditLog-007: INodeIdentityProvider resolution standardised on
GetRequiredService<>() (was mixed with GetService<>()).
- AuditLog-011: AddAuditLogHealthMetricsBridge guarded by sentinel
descriptor check — calling twice no longer double-registers the hosted
service.
Shutdown / supervision:
- SiteCallAudit-002: AkkaHostedService adds a CoordinatedShutdown
cluster-leave task (drain-site-call-audit-singleton) that issues a
bounded GracefulStop(10s) so failover waits for in-flight upserts.
Registration safety:
- NS-020: AkkaHostedService now guards NotificationForwarder S&F
registration with _notificationDeliveryHandlerRegistered + throws
InvalidOperationException on double-register to make the regression loud.
VERIFY-only closures:
- NotifOutbox-005: Confirmed already closed by CD-015 fix (ac96b83) —
NotificationOutboxRepository.InsertIfNotExistsAsync uses the same
raw-SQL IF NOT EXISTS + 2601/2627 swallow pattern; race eliminated.
5+ new regression tests (CentralUI sandbox WhenAll, ExternalCallResult
64-reader Barrier, AuditLog DI idempotency, RowVersion stale-throw,
SiteCallAudit-002 shutdown drain). Build clean; affected suites all green.
README regenerated: 65 open (was 75).
Caller-provided SourceNode wins (preserves reconciled rows from other nodes);
otherwise the writer fills it from the local INodeIdentityProvider.NodeName.
Reads from the provider on every write — singleton lifetime means zero overhead.
M4 Bundle B (B1) — add the central-only ICentralAuditWriter implementation
and inject it into NotificationOutboxActor so subsequent tasks (B2/B3) can
route attempt + terminal lifecycle events through the direct-write audit path.
- CentralAuditWriter: thin wrapper around IAuditLogRepository.InsertIfNotExistsAsync;
scope-per-call (matches AuditLogIngestActor / NotificationOutboxActor pattern);
stamps IngestedAtUtc; swallows all internal failures (alog.md §13).
- Registered as a singleton in AddAuditLog.
- NotificationOutboxActor ctor takes ICentralAuditWriter (validated non-null).
- Host wiring resolves the writer once from the root provider and passes it
into the singleton's Props.Create call.
- Existing TestKit fixtures updated with a NoOpCentralAuditWriter helper so
tests that don't exercise audit emission still compile and pass.
Bundle G of Audit Log #23 M2. Bridges the FallbackAuditWriter primary-
failure counter into the Site Health Monitoring report payload so a
sustained audit-write outage surfaces on /monitoring/health instead of
disappearing into a NoOp sink.
- SiteHealthReport: add SiteAuditWriteFailures (defaulted, additive).
- ISiteHealthCollector + SiteHealthCollector: new
IncrementSiteAuditWriteFailures() counter, per-interval reset
semantics matching ScriptErrorCount / DeadLetterCount.
- HealthMetricsAuditWriteFailureCounter: adapter forwarding
IAuditWriteFailureCounter.Increment() to the collector.
- AddAuditLogHealthMetricsBridge(): swaps the NoOp default
registration for the real bridge; called from
SiteServiceRegistration after AddSiteHealthMonitoring + AddAuditLog.
- Existing host-wiring test updated: site composition now resolves
HealthMetricsAuditWriteFailureCounter (not NoOp).
Tests: HealthMonitoring 60 -> 63 (3 new), AuditLog 56 -> 59 (3 new),
full solution green.
Wires Bundle E of the M2 site-sync pipeline:
- AddAuditLog extended to register the site writer chain (SqliteAuditWriter
singleton + ISiteAuditQueue forward + RingBufferFallback + FallbackAuditWriter
composing them) and the telemetry collaborators (SiteAuditTelemetryOptions,
SqliteAuditWriterOptions, IAuditWriteFailureCounter NoOp default,
ISiteStreamAuditClient NoOp default).
- AkkaHostedService central role: AuditLogIngestActor as ClusterSingletonManager
(singleton name 'audit-log-ingest') + ClusterSingletonProxy, mirroring the
Notification Outbox pattern. Proxy is offered to SiteStreamGrpcServer if it
resolves (Site path only today; M6 reconciliation will host gRPC on central).
- AkkaHostedService site role: SiteAuditTelemetryActor (per-site, NOT a
singleton because each site is its own cluster), bound to a dedicated
audit-telemetry-dispatcher (ForkJoinDispatcher, 2 dedicated threads).
- Program.cs + SiteServiceRegistration.Configure call AddAuditLog on both roles.
- AuditLogIngestActor gains a second constructor that takes IServiceProvider so
the cluster singleton can create a fresh scope per message — IAuditLogRepository
is a scoped EF Core service and cannot be pre-resolved from the root. The
IAuditLogRepository constructor remains for Bundle D's MSSQL-fixture tests.
NoOp ISiteStreamAuditClient is deliberate: no site→central gRPC channel exists
in M2 (sites talk to central via Akka ClusterClient; gRPC SiteStreamService is
hosted on sites for central→site streaming). M6 reconciliation introduces the
real gRPC site→central client + central-hosted gRPC server. Bundle H's
integration test substitutes a stub client directly via the actor's Props.
Tests:
- tests/ScadaLink.AuditLog.Tests/AddAuditLogTests.cs — 11 tests (was 3): writer
singleton, IAuditWriter as FallbackAuditWriter, ISiteAuditQueue same-instance
as SqliteAuditWriter, options bind round-trip, NoOp default assertions.
- tests/ScadaLink.Host.Tests/AkkaHostedServiceAuditWiringTests.cs (new) — 13
tests: BuildHocon emits audit-telemetry-dispatcher block with the expected
type/throughput/thread-count; Central composition root resolves the writer
chain + options; Site composition root resolves the writer chain + options +
NoOp client.
Verified: dotnet build clean, 23 test suites green (Host 194 + AuditLog 54).
Joseph Doherty