F1 (HIGH) DebugStreamBridgeActor: the 5-minute orphan net measured the MAILBOX
(SetReceiveTimeout), and once stream events were correctly marked
INotInfluenceReceiveTimeout nothing recurring reset it — the snapshot lands once
and GrpcStreamStable once — so every healthy session self-terminated at ~6 min
with a false "Site disconnected". Replaced with a periodic self-tick
(ConsumerLivenessCheckInterval, 30s) over a consumer-last-seen stamp renewed only
by DebugStreamConsumerAlive, which DebugStreamService Tells on a shared timer to
every session still in its registry (holding a session there IS "a consumer is
attached" — both the Blazor view and the SignalR hub release it on
dispose/disconnect, and it works headless). Reverting the wrapper was rejected: it
would restore the quiet-instance orphan bug.
F2 (MED) SiteStreamGrpcClient: the RpcException(Cancelled) filter now requires
cts.IsCancellationRequested. A peer-originated / channel-dispose Cancelled fired
none of onError/onCompleted/onConnected, leaving SiteAlarmAggregatorActor with
_streamDown=false forever (IsLive stuck true, reconcile reopen guard never fired).
F3 (MED) SiteStreamGrpcClient: a header TIMEOUT is no longer reported as
connected — that shape is exactly what an unreachable site produces, and it
cleared _streamDown, consumed _seedOnConnect and launched a full snapshot fan-out
at a dead site. AwaitHeadersAsync returns bool; the first received event is the
fallback connected signal, fired at most once from headers OR first event.
F4 (LOW-MED) SqliteAuditWriter.MarkReconciledUpToAsync: the blanket below-cursor
UPDATE retired late-stamped inserts that were never served (then age-purged —
silent loss). The flip is now bounded by insertion order: a Pending row retires
only if its rowid is at or below the high-water mark of rows this instance has
served from ReadPendingSinceAsync (clamped on purge, since SQLite reuses rowids);
Forwarded rows are exempt (central ACKed them over the push path). At-least-once
is unchanged.
F5 (LOW) Documented the liveness dependency (a served row never covered by a later
cursor stays Pending forever; PurgeExpiredAsync never purges Pending) in
ISiteAuditQueue + Component-AuditLog.md, and added a cheap site-health signal:
SiteAuditBacklogReporter logs a rate-limited warning when the existing
oldest-pending metric exceeds 24h.
F6 (MED) SiteAlarmAggregatorActor: _fanoutSinceLastTick was armed by the
reconcile's OWN fan-out, so steady state ran fan-out→skip→fan-out→skip — one
reconcile per 2x interval (120s), halving the not-reporting refresh and the alarm
reconcile backstop. The skip is now armed only by connect/failover-driven seeds
(initial, _seedOnConnect, and a re-seed queued behind one).
Tests: Communication.Tests 691 passed (+13), AuditLog.Tests 382 passed (+5).
Closes WP1.2 of the arch-review remediation plan (finding #2, High):
SqliteAuditWriterOptions.DatabasePath defaulted to CWD-relative "auditlog.db",
which on the docker rig resolves onto the container's ephemeral overlayfs
(not the mounted /app/data volume), silently discarding the pending audit
forward-state backlog on every recreate; nothing in docker/ or docker-env2/
overrode it; FlushIntervalMs was validated but never read by the writer loop
(one commit per event even at trickle rate); and no PRAGMA synchronous was
set (SQLite's FULL default fsyncs every commit).
- DatabasePath now has no default (mirrors ZB.MOM.WW.LocalDb's LocalDbOptions.Path)
and is required pre-host for Site nodes only, via a new StartupValidator raw-config
check (top-level "AuditLog:SiteWriter:DatabasePath", NOT nested under ScadaBridge:
AddAuditLog binds that section off the configuration root). SqliteAuditWriterOptionsValidator
deliberately does NOT check DatabasePath itself, because AddAuditLog runs its
ValidateOnStart on both Central and Site composition roots but only Site nodes
ever resolve the writer — checking it there would fail Central's boot too.
- All 8 site-node appsettings under docker/ and docker-env2/ now set
AuditLog:SiteWriter:DatabasePath to /app/data/auditlog.db (mounted volume,
survives container recreate, same convention as LocalDb:Path); the local-dev
base appsettings.Site.json sets ./data/auditlog.db to match.
- The writer loop now honors FlushIntervalMs: after draining the immediately
available burst, it keeps the transaction open (bounded by FlushIntervalMs
from the first event) waiting for more trickle-rate events before committing,
instead of flushing (and fsyncing) per event.
- PRAGMA synchronous = NORMAL on the write connection — audit is best-effort by
design (CLAUDE.md: "Audit-write failure NEVER aborts the user-facing action"),
so NORMAL's narrower power-loss window is an acceptable trade for far fewer
fsyncs; WAL mode still guarantees no corruption.
- Tests: StartupValidator site-required/blank/central-exempt cases; writer
trickle-load single-transaction coalescing + beyond-interval separate-transaction
regression (new FlushCountForTests seam); options-validator doc updates reflecting
the moved responsibility. Full suite runs green: AuditLog.Tests 368/368,
Host.Tests 480/480.
One-time migration note: the existing container-local auditlog.db (wherever it
landed under CWD) is abandoned by this change, not migrated — already-forwarded
rows are safe centrally (AuditLog is the durable copy), and any still-Pending
rows on the abandoned path are lost once. This is the exact bug being fixed, not
a new loss: those rows were already living outside the mounted volume and would
not have survived the next container recreate regardless. Cross-reference
docs/known-issues/2026-07-20-cached-telemetry-drain-hot-loop.md, which this
placement bug caused.
Joseph Doherty