The remediation reviews approved every task but left a tail of small notes.
This lands the gateway-side half of them.
Hardening (behavior changes, all narrow):
- BuildFilteredWriteBulkCommand's unreachable default case failed OPEN: a
fifth bulk-write kind added upstream without a filter case here would have
shipped the DENIED entries to the worker while reporting them denied to the
caller. It now throws UnreachableException.
- SqliteCanonicalAuditStore.ListRecentAsync no longer throws on a row it
cannot date. The retention sweep deliberately preserves such rows (SQLite's
datetime() yields NULL, so the DELETE never matches), which guaranteed the
dashboard's recent-audit view would meet one eventually and lose the whole
page to it. The row is now reported at DateTimeOffset.MinValue with every
other column intact, behind an optional logger.
- The audit drain loop's finally now completes the channel writer alongside
detaching the drain, so a producer that raced past the attached check takes
the write-through branch instead of stranding its event in a buffer nobody
reads until shutdown. TryComplete is idempotent, so StopAsync is unaffected.
Tests:
- MapCommandReply ownership (Assert.Same on the inner reply), mirroring the
existing MapEvent ownership test.
- Redactor key-id length boundary at exactly 64 and 65 characters, pinning
which way it fails. Nothing validates key-id length at creation, so
docs/Diagnostics.md's "which no issued key id does" is now stated as the
heuristic it is.
- ApiKeyFailureLimiter.Reset with a PartitionResolution whose partition was
evicted between the Check and the Reset: inert, and clears nobody else's
block.
- Constraint-cache concurrency stress: the cap is enforced by the inserting
thread, so overshoot must be transient and proportional to the in-flight
inserters, and the cache must settle at or under the cap.
- ListRecentAsync against a raw-SQL undateable row.
Comment/doc accuracy:
- EventsHubViewerRegistry.ReleaseConnection records that it relies on
SignalR's default sequential per-connection dispatch
(MaximumParallelInvocationsPerClient = 1).
- A PERF(followup) note on Invoke's double session resolve and why removing it
needs a SessionManager overload.
- SessionEventDistributor: the volatile-field comment named the pump as the
lock-free reader, but the pump's single capture point is inside _replayLock;
the genuinely lock-free reader is SubscriberCount. OnSubscriberOverflow's
"cannot be observed here" now excepts the DisposeAsync abandon path. The
churn test names its ConcurrentDictionary bucket-order assumption and that a
violation surfaces as a read timeout, not a silent pass.
- The two "restores the sequential drain's behavior" claims (SessionManager,
docs/Sessions.md) were wrong: the sequential drain leaked too, because
KillWorkerAsync's entry ThrowIfCancellationRequested aborted the whole loop
on the first session for zero kills. Reworded to "fixes a leak the
sequential drain also had", with the sweep-bound/shutdown-unbound
ParallelOptions asymmetry explained.
- ISessionManager.ShutdownAsync's token doc: it degrades the drain to a kill
sweep rather than cancelling it, with the bounded overrun stated.
SessionShutdownHostedService.StopAsync records that its cancellation-logging
branch is now unreachable.
DashboardEventBroadcaster.Publish ran a deep protobuf Clone (redaction is on by
default) and a group SendAsync for every event of every session, before anything
checked whether a dashboard client was actually watching. In the steady state the
session:{id} group is empty, so that work was thrown away per event.
SignalR does not expose group membership, so EventsHub now mirrors its own
add/remove into a singleton EventsHubViewerRegistry, and OnDisconnectedAsync
releases everything a dropped connection held (SessionDetailsPage disposes the
connection rather than unsubscribing). Publish returns early when the session has
no viewers, before the redaction clone. Watched sessions behave exactly as before.
Lazy mirror-lease start/stop was deliberately not attempted — it entangles the
dashboard with SessionEventDistributor subscribe lifetime for no saving beyond
this gate; recorded in docs/GatewayDashboardDesign.md.
Joseph Doherty