The snapshot's per-site stalled latch now lives on the snapshot itself
and is fed by SiteAuditTelemetryStalledTracker via ApplyStalled, removing
the chain that required ActorSystem at DI composition time. The tracker
is now constructed by AkkaHostedService once ActorSystem.Create returns,
with a lock-guarded auxiliary-disposable list so concurrent host
start/stop in tests cannot race the enumeration.
Central singleton (M6-T4 Bundle C) that drives the daily AuditLog partition
purge. On a configurable timer (default 24 hours) the actor:
1. Queries IAuditLogRepository.GetPartitionBoundariesOlderThanAsync for
monthly boundaries whose latest OccurredAtUtc is older than
DateTime.UtcNow - AuditLogOptions.RetentionDays.
2. For each eligible boundary calls SwitchOutPartitionAsync, which runs
the drop-and-rebuild dance around UX_AuditLog_EventId.
3. Publishes AuditLogPurgedEvent(boundary, rowsDeleted, durationMs) on
the actor-system EventStream so the Bundle E central health collector
and ops surfaces can subscribe without coupling to this actor.
Co-changes:
* SwitchOutPartitionAsync returns long (rows deleted) — sampled BEFORE the
switch via COUNT_BIG over the per-partition filter so the count
reflects what the switch removed, not a post-purge scan of a table that
no longer exists. All stub implementations updated.
* AuditLogPurgeOptions: IntervalHours (default 24), IntervalOverride for
tests, Interval property resolving either.
* AuditLogPurgedEvent: record with MonthBoundary, RowsDeleted, DurationMs.
Behavior:
* Continue-on-error per boundary — one partition that throws does NOT
abandon the rest of the tick.
* DI scope opened per tick (IAuditLogRepository is a SCOPED EF Core
service); mirrors SiteAuditReconciliationActor and AuditLogIngestActor.
* SupervisorStrategy Resume keeps the singleton alive across leaked
exceptions.
* EventStream capture BEFORE the first await — Context is unsafe after
await in async receive handlers (same pattern as Sender-capture in
AuditLogIngestActor.OnIngestAsync).
Tests:
* Tick_Fires_OnDailyInterval — visible timer side effect.
* Tick_OldPartitions_SwitchedOut — both seeded boundaries purged.
* Tick_NewerPartitions_Untouched — empty enumerator → no switches.
* Tick_PublishesPurgedEvent_WithRowCount — AuditLogPurgedEvent carries
RowsDeleted and DurationMs.
* Tick_SwitchThrows_OtherPartitionsStillProcessed — continue-on-error.
* Threshold_UsesAuditLogOptionsRetentionDays — non-default 30-day window
computed from UtcNow - RetentionDays.
* EndToEnd_RealPartition_RowsRemoved_PurgedEventPublished — TestKit +
MsSqlMigrationFixture: real partitioned table, Jan-2026 row purged,
Apr-2026 row kept, AuditLogPurgedEvent observed via probe.
Bundle C task M5-T7 — surface DefaultAuditPayloadFilter redactor
over-redactions as a Site Health metric so a misconfigured /
catastrophic regex shows up on /monitoring/health rather than
disappearing into a NoOp sink.
- SiteHealthReport: new 'AuditRedactionFailure' int field
(defaulted to 0 for back-compat with existing producers/tests).
- ISiteHealthCollector / SiteHealthCollector:
new IncrementAuditRedactionFailure() — per-interval atomic
counter with Interlocked, reset on CollectReport, mirroring
the M2 Bundle G SiteAuditWriteFailures pattern.
- HealthMetricsAuditRedactionFailureCounter: new bridge in
ScadaLink.AuditLog.Site that forwards IAuditRedactionFailureCounter
increments to ISiteHealthCollector — mirrors
HealthMetricsAuditWriteFailureCounter one-for-one.
- AddAuditLogHealthMetricsBridge: now ALSO Replaces the
NoOpAuditRedactionFailureCounter binding with the health-metrics
bridge, so a single AddAuditLogHealthMetricsBridge() call wires
both the M2 Bundle G write-failure counter and the M5 Bundle C
redaction-failure counter into the health report.
Site-side only for M5 — the filter also runs on CentralAuditWriter
and AuditLogIngestActor (where it just keeps the NoOp default), but
a central-side health-metric surface for AuditRedactionFailure is
deferred to M6 alongside the rest of the central health collector
work.
Tests:
- AuditRedactionFailureMetricTests (HealthMonitoring) covers the
SiteHealthCollector increment/report/reset shape (3 tests).
- HealthMetricsAuditRedactionFailureCounterTests (AuditLog) covers
the AuditLog → HealthMonitoring bridge (3 tests).
- Existing CountCapturingHealthCollector stub in
DeploymentManagerRedeployTests extended with the new no-op
interface method.
Verified: dotnet build clean, all 24 test projects green
(the only Failed at first ScadaLink.SiteRuntime.Tests run was the
known-flaky InstanceActorChildAttributeRaceTests; passes on re-run
in isolation and full suite, unrelated to these changes).
Bundle C task M5-T6 — plugs the IAuditPayloadFilter singleton into the
three audit writer entry points so every event is truncated + redacted
before persistence, regardless of which path it took to disk:
- FallbackAuditWriter (site hot path): filter runs before the primary
SQLite write AND the ring-buffer enqueue, so a recovery drain replays
rows that are already capped/redacted.
- CentralAuditWriter (central direct-write): filter runs before the
per-call IAuditLogRepository.InsertIfNotExistsAsync.
- AuditLogIngestActor (site→central telemetry):
- OnIngestAsync resolves the filter from the per-message scope and
applies it to each row before IngestedAtUtc stamping.
- OnCachedTelemetryAsync (M3 dual-write) applies the filter to the
audit half of every CachedTelemetryEntry before the audit-insert
+ site-call-upsert transaction.
Filter parameter is optional (nullable) on each constructor so the
existing test composition roots that don't pass one keep working unchanged
— production DI wiring in AddAuditLog always passes the real filter
through. ICentralAuditWriter registration switched from the open-ctor
form to a factory so the filter flows through it.
Tests: FilterIntegrationTests covers all three writer paths end-to-end
(4 tests). Full ScadaLink.AuditLog.Tests suite: 146 passed, 0 failed,
0 skipped.
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.
M3 Bundle F (Task F1) wires the cached-call audit pipeline through the
composition roots:
- Central: register SiteCallAuditActor as a cluster singleton + proxy
(mirrors AuditLogIngestActor and NotificationOutboxActor). Program.cs
calls .AddSiteCallAudit() on the central role.
- Site: register ICachedCallTelemetryForwarder + CachedCallLifecycleBridge
in AddAuditLog (lazy factory — Central nodes degrade to audit-only
emission because IOperationTrackingStore is site-only).
- Site: bind CachedCallLifecycleBridge to ICachedCallLifecycleObserver so
StoreAndForwardService picks it up via DI.
- Site: introduce IStoreAndForwardSiteContext + Host adapter to surface the
site id to StoreAndForwardService without creating a
StoreAndForward -> HealthMonitoring project-reference cycle.
- ScriptExecutionActor resolves ICachedCallTelemetryForwarder per script
scope and threads it into ScriptRuntimeContext.
CachedCallTelemetryForwarder's IOperationTrackingStore dependency is now
nullable so Central DI validation succeeds with the lazy registration; the
forwarder's tracking-half emission is a no-op when the store is absent.
Tests:
- AkkaHostedServiceAuditWiringTests: Central host builds with
AddSiteCallAudit and resolves ICachedCallTelemetryForwarder; Site
resolves the forwarder + bridge + observer + IStoreAndForwardSiteContext.
- Full solution: 194 Host tests green, 241 SiteRuntime tests green, every
other suite unchanged.
Wire the M3 cached-call audit pipeline end-to-end for the database
channel and close the loop between the S&F lifecycle observer and the
site-side dual emitter.
* DatabaseCachedWriteEmissionTests covers Database.CachedWrite (set up
in Bundle E3): mints a TrackedOperationId, emits one CachedSubmit
packet on DbOutbound, threads the id into IDatabaseGateway, and is
best-effort on a thrown forwarder. Mirrors ExternalSystem.CachedCall
coverage from E3.
* CachedCallLifecycleBridge (new) implements ICachedCallLifecycleObserver
and lives alongside CachedCallTelemetryForwarder. The bridge ingests
per-attempt notifications from the S&F retry loop and fans them out
to the forwarder:
- TransientFailure -> 1 Attempted row
- Delivered -> Attempted + CachedResolve(Delivered)
- PermanentFailure -> Attempted + CachedResolve(Parked)
- ParkedMaxRetries -> Attempted + CachedResolve(Parked)
Channel string -> AuditKind mapping (ApiOutbound->ApiCallCached,
DbOutbound->DbWriteCached). Best-effort top-level catch swallows any
unexpected throw so the S&F retry bookkeeping is never disturbed.
* Bridge tests (7) cover all four outcomes, channel mapping, provenance
propagation, and the no-throw-on-forwarder-failure contract.
Bundle F (Host registration) will instantiate the bridge and inject it
into StoreAndForwardService.cachedCallObserver, closing the wiring path
end-to-end.
Bundle E task E6.
Rework ScriptRuntimeContext.ExternalSystem.CachedCall to fit the M3
combined-telemetry model:
* Mints a fresh TrackedOperationId and emits one CachedSubmit packet
via ICachedCallTelemetryForwarder BEFORE handing the call off — the
SiteCalls row is materialised before the first delivery attempt so
Tracking.Status(id) can observe a Submitted row even if immediate
delivery resolves before the helper returns.
* Threads the TrackedOperationId into IExternalSystemClient.CachedCallAsync
as a new optional parameter (and into IDatabaseGateway.CachedWriteAsync
for the Database mirror set up here for E6). The gateway uses the id
as the StoreAndForward messageId so the retry loop (Tasks E4/E5) can
recover it from StoreAndForwardMessage.Id.
* Returns the TrackedOperationId rather than ExternalCallResult — the
script's contract is now "get a tracking handle, observe outcome via
Tracking.Status". Best-effort emission: a thrown forwarder is logged
+ swallowed; the original call still runs and the id is still returned.
DatabaseHelper gets the matching siteId / sourceScript / forwarder
fields and a parallel CachedSubmit emitter (Channel=DbOutbound) so Task
E6's Database.CachedWrite mirror plugs in without further runtime
wiring.
New ICachedCallTelemetryForwarder seam in Commons.Interfaces.Services
so SiteRuntime depends on Commons (existing arrow) rather than
ScadaLink.AuditLog (would have introduced a new dependency).
Bundle E task E3 (and helper-shape work for E6).
Sister to SiteAuditTelemetryActor: takes a combined CachedCallTelemetry
packet and fans it out to the two site-local stores.
* AuditEvent half writes through IAuditWriter (the M2 FallbackAuditWriter
+ SqliteAuditWriter chain — same site SQLite hot-path as sync calls).
* SiteCallOperational half maps Audit.Kind to the matching
IOperationTrackingStore method:
- CachedSubmit -> RecordEnqueueAsync (insert-if-not-exists)
- ApiCallCached / DbWriteCached -> RecordAttemptAsync (monotonic)
- CachedResolve -> RecordTerminalAsync (first-write-wins)
Best-effort contract (alog.md §7): independent try/catch per half so a
thrown writer cannot starve the tracking row (and vice-versa); both
failures are logged at warning level and swallowed — the calling script
never sees them.
Wire push deferred to M6 — the NoOp ISiteStreamAuditClient binding stays
in effect; the forwarder writes only to the local stores in M3. The
existing SiteAuditTelemetryActor drain loop will sweep the audit rows
once a real gRPC client lands.
Bundle E task E2.
Add the second site→central RPC seam alongside the existing M2
IngestAuditEventsAsync. The Bundle D proto already lit up
IngestCachedTelemetry (CachedTelemetryBatch / IngestAck) so this commit
just plumbs the client-side abstraction:
* ISiteStreamAuditClient gains IngestCachedTelemetryAsync(batch, ct).
* NoOpSiteStreamAuditClient implements it returning an empty IngestAck
(same shape as M2 — production gRPC client lands in M6).
* SyncCallEmissionEndToEndTests' DirectActorSiteStreamAuditClient stub
throws NotSupportedException from the new method so a regression that
accidentally routes a cached packet through the sync stub fails loudly.
* New NoOpSiteStreamAuditClientTests cover the null-guard + empty-ack
contract for both batch shapes.
Bundle E task E1.
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).
Adds the IAuditWriter composer that sits between the script-side
ScriptRuntimeContext audit emission (Bundle F) and the primary
SqliteAuditWriter. Honours the alog.md §7 guarantee that audit-write
failures NEVER abort the user-facing action:
- Primary throw -> log Warning, increment IAuditWriteFailureCounter
(Bundle G's health-metric sink), stash the event in the drop-oldest
RingBufferFallback, return success to the caller.
- Primary success -> opportunistically drain the ring back through the
primary in FIFO order, behind the triggering event. Drain is
serialised via a SemaphoreSlim gate so concurrent recoveries don't
double-replay; a drain-side re-throw re-enqueues at the tail and
breaks out (the next successful write retries).
Adds IAuditWriteFailureCounter as the lightweight DI seam (one void
Increment()), and a TryDequeue helper on RingBufferFallback that the
recovery path uses to pop one item without blocking.
Tests (4 new, total 26 -> 30):
- WriteAsync_PrimaryThrows_EventLandsInRing_CallReturnsSuccess
- WriteAsync_PrimaryRecovers_RingDrains_InFIFOOrder_OnNextWrite
(order: trigger first, then ring backlog in submission FIFO)
- WriteAsync_PrimaryAlwaysSucceeds_Ring_StaysEmpty
- WriteAsync_FailureCounter_Incremented_Per_PrimaryFailure
Adds RingBufferFallback — an in-memory drop-oldest ring buffer used by
the upcoming FallbackAuditWriter (Bundle B-T4) when the primary SQLite
writer is throwing. Backed by Channel<AuditEvent> with
BoundedChannelFullMode.DropOldest, fixed capacity (default 1024).
Channel.CreateBounded(DropOldest) does NOT natively signal a drop on
TryWrite, so overflow is detected by comparing Reader.Count before and
after the enqueue: when the buffer is already at capacity and a new
TryWrite succeeds while keeping the count at capacity, exactly one
event was displaced and RingBufferOverflowed is raised (one event per
drop).
Public surface:
- bool TryEnqueue(AuditEvent) — always succeeds unless completed.
- IAsyncEnumerable<AuditEvent> DrainAsync(CancellationToken) — FIFO.
- void Complete() — closes the channel so DrainAsync can finish.
- event Action? RingBufferOverflowed — health counter hook.
Tests (3 new, total 23 -> 26):
- Enqueue_1025_Into_1024Cap_Ring_DropsOldest_AndRaisesOverflowOnce
- DrainAsync_Yields_FIFO_Then_Completes_When_Empty
- TryEnqueue_AllSucceeds_ReturnsTrue
Replaces the B-T1 stub WriteAsync with the production hot-path:
- Bounded Channel<PendingAuditEvent> (BoundedChannelFullMode.Wait, capacity
from options) feeds a background ProcessWriteQueueAsync loop that drains
up to BatchSize events per transaction.
- The loop INSERTs each event with explicit parameter binding (enums and
DateTime stored as text); duplicate EventIds (SqliteException with
ErrorCode 19 SQLITE_CONSTRAINT) are swallowed as first-write-wins per
alog.md §11, and the pending TCS is still completed successfully so
callers see idempotent semantics.
- Site rows force ForwardState = Pending on enqueue when the inbound
event leaves it null — site-side default per the M2 design.
- ReadPendingAsync(limit) returns oldest-first pending rows for the
Bundle D telemetry actor; EventId is the deterministic tiebreaker on
identical OccurredAtUtc timestamps. MarkForwardedAsync(ids) flips a
batch to Forwarded in one UPDATE with a parameterised IN list.
- IAsyncDisposable graceful shutdown: TryComplete the writer, await the
drain (5s budget), then dispose the connection.
Tests (7 new, total 16 -> 23):
- WriteAsync_FreshEvent_PersistsWithForwardStatePending
- WriteAsync_Concurrent_1000Calls_All_Persist_NoExceptions
- WriteAsync_DuplicateEventId_FirstWriteWins_NoException
- WriteAsync_ForcesForwardStatePending_IfNull
- ReadPendingAsync_Returns_OldestFirst_LimitedToN
- MarkForwardedAsync_FlipsRowsToForwarded
- MarkForwardedAsync_NonExistentId_NoThrow
