Async cancellation hygiene, fire-and-forget observability, retry/shutdown
semantics, and audit-row coverage across 9 modules. Highlights:
Cancellation & lifecycle:
- AuditLog-006: SqliteAuditWriter.Dispose hops to thread pool, escaping the
captured SyncContext that risked sync-over-async deadlock.
- AuditLog-010: SiteAuditTelemetryActor owns a private lifecycle CTS,
threaded through drain paths instead of CancellationToken.None.
- Comm-019: CentralCommunicationActor adds lifecycle CTS for repo calls.
- Host-019: Migration StartupRetry forwards ApplicationStopping so SIGTERM
during the bounded-retry window aborts cleanly.
Cursor / retry / counter correctness:
- AuditLog-004: SiteAuditReconciliationActor's cursor now holds at `since`
when any row's idempotent insert is still being retried (per-EventId
retry counter, MaxPermanentInsertAttempts=5 escape valve with LogCritical
abandon). No more silent abandonment of permanently-failing rows.
- ConfigDB-019: Dropped the catch-and-continue on EnsureLookaheadAsync's
SPLIT loop — by class-doc construction the catch could only mask real
failures and let the next iteration create permanent partition holes.
- HM-017/018: HealthReportSender + CentralHealthReportLoop snapshot
per-interval counters before sending, restore via new
ISiteHealthCollector.AddIntervalCounters on transport failure so counts
aren't silently lost.
Fire-and-forget / shutdown waits:
- InboundAPI-018: AuditWriteMiddleware observes faulted audit-write tasks
via OnlyOnFaulted continuation (Warning log; response unchanged).
- SnF-024: StoreAndForwardService.StopAsync awaits in-flight retry sweep
with a bounded SweepShutdownWaitTimeout (10s).
Leak / refactor:
- Comm-021: SiteStreamGrpcServer.SubscribeInstance wraps Subscribe in its
own try/catch so a throw doesn't leak the relay actor or _activeStreams
entry.
- Comm-022: VERIFIED already-closed by Comm-016's dead-code purge.
- CLI-017: BundleCommands' three subcommands delegate to ExecuteCommandAsync
(auth-failure exit-code contract unified).
Defensive / validation:
- CLI-021: CliConfig.Load wraps file-read/JSON parse so malformed config
prints a warning and returns defaults instead of crashing the CLI.
- Host-022: ParseLevel emits stderr one-shot warning for unrecognised
MinimumLevel instead of silently coercing to Information.
- ESG-019: ExternalSystemClient sets HttpClient.Timeout=Infinite so the
per-call CTS is the sole timeout source (was clipped to 100s by .NET).
- Security-020: New SecurityOptionsValidator (IValidateOptions) rejects
empty LdapServer/LdapSearchBase with ValidateOnStart.
- DM-019: Lifecycle command timeouts now emit DisableTimedOut/EnableTimedOut/
DeleteTimedOut audit entries (mirrors DeployFailed pattern).
Plus reconciled stale per-module Open-findings counters that had drifted
from prior sessions.
20+ new regression tests across 11 test projects; build clean; affected
suites all green. README regenerated: 75 open (was 93).
Comm-016: delete dead HandleConnectionStateChanged + _debugSubscriptions /
_inProgressDeployments tracking + ConnectionStateChanged message record.
Disconnect detection is owned by the transport layers (gRPC keepalive PING
~25s; Ask-timeout at CommunicationService). Updates the
Component-Communication.md design doc to make that explicit.
SnF-018: NotificationForwarder.DeliverAsync now discards a corrupt buffered
payload (Warning log + return true) instead of returning false and parking
the row — honoring the design's "notifications do not park" invariant.
DM-018: reconciliation no longer force-sets Enabled, preserving an
intentional Disabled state after central failover.
ESG-018: DeliverBufferedAsync (both ExternalSystemClient + DatabaseGateway)
catches JsonException and returns false, turning a corrupt buffered row
into a parked operation instead of a retry-forever poison message.
InboundAPI-022: register ActiveNodeGate as IActiveNodeGate in the Central
DI branch so standby-node gating is actually wired up in production.
NS-019: remove orphaned NotificationDeliveryService /
INotificationDeliveryService / NotificationResult; central notification
delivery now lives entirely in NotificationOutbox.
SEL-016: normalise From/To filters to UTC before ISO-string compare so
non-UTC DateTimeOffset clients no longer get spuriously excluded events.
TE-017: include Description on attributes/alarms and a HashableConnections
projection (protocol, endpoint JSON, failover count) in the revision hash
and DiffService; staleness detection now catches description-only and
connection-endpoint edits.
Transport-001 and Transport-002 (also High) remain Open — they're being
handled in a follow-up batch because both touch BundleImporter.cs and
must serialise.
The store-and-forward retry loop emits the per-attempt and terminal cached
audit rows (ApiCallCached/DbWriteCached Attempted, CachedResolve) via
CachedCallLifecycleBridge from a CachedCallAttemptContext, not from the
script context. The ExecutionId rollout (Task 4) already threaded ExecutionId
and SourceScript through this path; ParentExecutionId — the spawning
inbound-API request's ExecutionId — was not, so those retry-loop rows had
ParentExecutionId = null even for an inbound-API-routed run.
Thread it additively as a sibling at every carry point ExecutionId passes
through:
- StoreAndForwardMessage gains ParentExecutionId (Guid?).
- StoreAndForwardStorage adds a nullable parent_execution_id column via the
same idempotent PRAGMA-probed ALTER TABLE migration; rows persisted by an
older build read back null (back-compat). The defensive Guid.TryParse read
helper (ParseExecutionId) is renamed ParseGuidColumn and reused for both
columns so a corrupt value cannot abort the retry sweep.
- StoreAndForwardService.EnqueueAsync gains an optional parentExecutionId
param, stamped onto the buffered message and surfaced on the
CachedCallAttemptContext built in the retry loop.
- CachedCallAttemptContext gains ParentExecutionId.
- CachedCallLifecycleBridge.BuildPacket sets AuditEvent.ParentExecutionId
from the context, beside the existing ExecutionId.
- IExternalSystemClient.CachedCallAsync / IDatabaseGateway.CachedWriteAsync
gain an optional parentExecutionId param; ScriptRuntimeContext's CachedCall
/ CachedWrite helpers pass _parentExecutionId.
All threading is additive — ParentExecutionId is Guid? everywhere, null for
non-routed runs, and old buffered S&F rows still deserialize with the new
field null.
The store-and-forward retry loop emits the per-attempt and terminal cached
audit rows (ApiCallCached/DbWriteCached Attempted, CachedResolve) via
CachedCallLifecycleBridge from a CachedCallAttemptContext, not from the
script context. ExecutionId (and SourceScript) were not threaded through the
S&F buffer, so those rows had ExecutionId = null and SourceScript = null.
Thread both, additively, from the cached-call enqueue path:
- StoreAndForwardMessage gains ExecutionId (Guid?) / SourceScript (string?).
- StoreAndForwardStorage adds nullable execution_id / source_script columns
via an idempotent PRAGMA-probed ALTER TABLE migration; rows persisted by
an older build read back null (back-compat).
- StoreAndForwardService.EnqueueAsync gains optional executionId /
sourceScript params, stamped onto the buffered message and surfaced on the
CachedCallAttemptContext built in the retry loop.
- CachedCallAttemptContext gains ExecutionId / SourceScript.
- CachedCallLifecycleBridge.BuildPacket sets AuditEvent.ExecutionId and
AuditEvent.SourceScript from the context (replacing the hard-coded
SourceScript = null and its now-stale comment).
- IExternalSystemClient.CachedCallAsync / IDatabaseGateway.CachedWriteAsync
gain optional executionId / sourceScript params; ScriptRuntimeContext's
CachedCall / CachedWrite helpers pass _executionId / _sourceScript.
Script-side cached rows (CachedSubmit, immediate Attempted+Resolve) are
unchanged. All threading is additive — old buffered S&F rows still
deserialize and process with the new fields null.
Hook the store-and-forward retry loop so the audit pipeline can emit
per-attempt + terminal telemetry under the original TrackedOperationId
(Bundle E Tasks E4 + E5).
New seam:
* ICachedCallLifecycleObserver + CachedCallAttemptContext in
Commons.Interfaces.Services. Outcome enum
(Delivered / TransientFailure / PermanentFailure / ParkedMaxRetries)
is S&F-vocabulary; the bridge living in ScadaLink.AuditLog (Bundle F)
will map it to the AuditKind/AuditStatus pair when building the
CachedCallTelemetry packet.
* StoreAndForwardService gains an optional cachedCallObserver
constructor parameter + siteId. RetryMessageAsync fires the observer
exactly once per attempt with the appropriate outcome:
- handler returns true -> Delivered
- handler returns false -> PermanentFailure (and parks)
- handler throws + retries remaining -> TransientFailure
- handler throws + max retries hit -> ParkedMaxRetries (and parks)
Hook is best-effort: a thrown observer is logged + swallowed so a
failing audit pipeline can never be misclassified as a transient
delivery failure or corrupt the retry-count bookkeeping (alog.md §7).
Only cached-call categories (ExternalSystem, CachedDbWrite) generate
notifications — Notification category has its own central-side
audit pipeline (Notification Outbox / #21).
Pre-M3 callers that didn't thread a TrackedOperationId into the S&F
message id are silently skipped — the observer requires a parseable id
by contract. New S&F callers stamp the id as messageId (Bundle E3).
Bundle E tasks E4 + E5.
Notify.To(list).Send(subject,body) now generates a NotificationId GUID,
enqueues a Notification-category message into the site Store-and-Forward
Engine, and returns the NotificationId immediately (Task<string>). The
NotificationId is the single idempotency key end-to-end: it is the S&F
message Id, it is carried inside the buffered NotificationSubmit payload,
and it is the id the forwarder submits to central.
NotificationForwarder now deserializes the buffered payload as a
NotificationSubmit and reads NotificationId from it (re-stamping only the
site-owned SourceSiteId / SourceInstanceId), instead of deriving the id
from StoreAndForwardMessage.Id.
Adds NotifyHelper.Status(id): queries central via the site communication
actor; reports the site-local Forwarding state while the notification is
still buffered at the site, maps central's response when found, and
Unknown otherwise. Adds a NotificationDeliveryStatus record.
SiteCommunicationActor gains a NotificationStatusQuery forwarding handler
mirroring NotificationSubmit. StoreAndForwardService.EnqueueAsync gains an
optional messageId parameter and exposes GetMessageByIdAsync.
StoreAndForwardStorage.InitializeAsync opened a SqliteConnection against the
configured SqliteDbPath (default ./data/store-and-forward.db) without ensuring
the parent directory exists. SQLite creates the database file but not its
directory, so when data/ was absent the connection failed with
"SQLite Error 14: unable to open database file" — aborting the site host's
RegisterSiteActors at StoreAndForwardService.StartAsync.
This was the root cause of the six failing SiteActorPathTests. Production
masked it because the Docker image / deployment creates data/.
InitializeAsync now calls EnsureDatabaseDirectoryExists, which parses the
connection string and creates the parent directory of a file-backed database
(in-memory databases and bare filenames are skipped).
Regression test InitializeAsync_FileInMissingDirectory_CreatesDirectory fails
against the pre-fix code. Host suite now 155/155 green (was 149/155).
Resolves StoreAndForward-001, ExternalSystemGateway-001, NotificationService-001
— one systemic gap where buffered messages were persisted but never delivered,
and the active node never replicated its buffer to the standby.
Delivery handlers (ExternalSystemGateway-001 / NotificationService-001):
- AkkaHostedService registers delivery handlers for the ExternalSystem,
CachedDbWrite and Notification categories after StoreAndForwardService starts;
each resolves its scoped consumer in a fresh DI scope.
- ExternalSystemClient, DatabaseGateway and NotificationDeliveryService each
gain a DeliverBufferedAsync method: re-resolve the target and re-attempt
delivery, returning true/false/throwing per the transient-vs-permanent contract.
- EnqueueAsync gains an attemptImmediateDelivery flag; CachedCallAsync and
NotificationDeliveryService.SendAsync pass false (they already attempted
delivery themselves) so registering a handler does not dispatch twice.
Replication (StoreAndForward-001):
- ReplicationService is injected into StoreAndForwardService; a new BufferAsync
helper replicates every enqueue, and successful-retry removes and parks are
replicated too. Fire-and-forget, no-op when replication is disabled.
Tests: StoreAndForwardReplicationTests (Add/Remove/Park observed),
attemptImmediateDelivery behaviour, and DeliverBufferedAsync paths for each
consumer. Full solution builds; StoreAndForward/ExternalSystemGateway/
NotificationService suites green.
Move all package versions into Directory.Packages.props so every project
resolves a single consistent version. Consolidates the Roslyn packages
(Microsoft.CodeAnalysis.CSharp.Scripting/Workspaces) onto 5.0.0, which
resolves the pre-existing NU1608 version-skew error in the test projects.
Restore inside the docker build was failing because TreatWarningsAsErrors
promotes NU1902/NU1903/NU1904 (vulnerable package warnings) to errors.
Bump the flagged packages to advisory-free versions:
- MailKit 4.15.1 -> 4.16.0 (GHSA-9j88-vvj5-vhgr)
- Microsoft.AspNetCore.DataProtection.EFCore 10.0.5 -> 10.0.7 (GHSA-9mv3-2cwr-p262, transitively pulls fixed System.Security.Cryptography.Xml — GHSA-37gx-xxp4-5rgx, GHSA-w3x6-4m5h-cxqf)
- OpenTelemetry.Api (transitive via Akka.Hosting) 1.9.0 -> 1.15.3 (GHSA-g94r-2vxg-569j, GHSA-8785-wc3w-h8q6) — added as a direct PackageReference in ScadaLink.Host to override the Akka.Hosting pin
To resolve the NU1605 downgrade chain triggered by DataProtection.EFCore
10.0.7 (which transitively requires Microsoft.EntityFrameworkCore >= 10.0.7
and friends), bump every Microsoft.* 10.0.5 reference across src/ and
tests/ to 10.0.7 in lockstep.
17 source projects (Commons + Host + 15 components) and 17 xUnit test projects.
SLNX format, net10.0, nullable enabled, warnings as errors. All components
reference Commons; Host references all components. Builds and tests clean.
Joseph Doherty