P5-3: add IX_Notifications_Created_NotificationId (CreatedAt DESC,
NotificationId DESC) — the Central UI Notification Outbox list page sorts on
exactly that pair, but no existing index leads unconditionally on CreatedAt,
so an unfiltered/lightly filtered page fell back to a full clustered-index
scan + sort on every COUNT + page request. Mirrors the Medium wave's
IX_SiteCalls_Created_TrackedOperationId migration + SQL twin pattern
faithfully, including the handwritten docs/plans/sql script.
P5-4: operator Retry/Discard was read-check-write keyed on NotificationId
only — a detached PipeTo task interleaving with the dispatcher's own write
(or a second concurrent operator action) could land between the read and
the write and get silently clobbered by the unconditional UpdateAsync,
stamping a Delivered row Discarded with stale fields. Adds
INotificationOutboxRepository.TryUpdateFromParkedAsync, a single-statement
compare-and-swap (WHERE Status == Parked) mirroring
SecuredWriteRepository.TryMarkApprovedAsync's CAS shape. NotificationOutboxActor's
RetryAsync/DiscardAsync now use the CAS write and, on a lost race, re-read
to report "notification already progressed to <Status>" instead of silently
overwriting whatever is there now.
Proof of failure: reverting only the actor's CAS usage while keeping the
repository addition reproduces the silent-overwrite bug — 7 tests fail,
including two new deterministic (non-sleep) race-proof tests that mock the
exact GetByIdAsync -> lost-CAS -> re-read sequence the finding describes.
P5-3 is perf-only; verified via migration/SQL-twin parity instead (no
runtime proof-of-failure is meaningful for an index).
Six adversarial-review findings in the central SQL/ingest layer.
F1 (AuditLogRepository.InsertChunkAsync) — the set-based ingest declared each
string parameter at its COLUMN width (Actor/Target 256, Action 64, Outcome 16,
Category 32, SourceNode 64), so SqlClient truncated an over-long value at bind
time and committed the mutilated row — silent, in an append-only store, with no
PayloadTruncated flag — while the per-row and reconciliation paths sent the same
value in full and let the server reject it with 2628. Bind at the value's own
length instead; explicit SqlDbType is kept (it fixes the VALUES constructor's
derived column types and datetime2 precision). Design: reject everywhere,
truncate nowhere — matching today's per-row behaviour.
F2 (SiteCallAuditRepository.UpsertAsync) — the single-statement upsert ran the
monotonic UPDATE first and INSERTed only if nothing matched. Two writers racing
the first packet of one TrackedOperationId (the cached dual-write and the
reconciliation pull carry DIFFERENT lifecycle states) both matched nothing, and
the loser then skipped its INSERT or swallowed a 2627 — dropping its
Status/RetryCount/HttpStatus/TerminalAtUtc. Legs swapped to
`IF NOT EXISTS … INSERT; UPDATE <monotonic>` — still one round trip, and the
loser's UPDATE now lands on the winner's row. The duplicate-key catch re-runs
the monotonic UPDATE for the same reason. Moved to raw SQL with explicitly-typed
parameters so the intricate rank predicate exists in exactly one place (an
untyped DateTime would bind as `datetime` and round the freshness tiebreaker).
F3 (docs/plans/sql/*.sql) — filtered-index DDL failed with error 1934 under the
documented `docker exec … sqlcmd` path, which defaults QUOTED_IDENTIFIER OFF;
once IX_Notifications_Delivered exists, QI-OFF DML on Notifications fails too.
All four scripts now open with `SET QUOTED_IDENTIFIER ON; SET ANSI_NULLS ON; GO`
(own batch, so it is in force when the next batch parses), and the migration
convention in Component-ConfigurationDatabase.md documents `sqlcmd -I`. Verified
live: the pre-fix script fails 1934 without -I, the fixed one applies.
F4 (SiteCallAuditActor) — the off-mailbox reconciliation/purge passes reuse the
injected repository, so tests drove one DbContext from the pass and a mailbox
handler concurrently. Serialized at the CALL via a private SerializedRepository
wrapper applied only by the test constructors, rather than running the pass
on-mailbox: production keeps its PipeTo shape untouched, and the existing
"a blocked drain does not stall ingest/query/KPI" regression tests stay
meaningful (they would have been invalidated by suspending the mailbox).
F5 (AuditLogIngestActor) — when the batch failed because the 20 s IngestBudget
expired, the per-row fallback reused the same expired token: N instant failures,
N counter bumps, zero accepted. The fallback now gets a fresh 5 s budget (inside
the 30 s outer Ask), and a blown budget bumps the failure counter ONCE for the
batch instead of once per row.
F6 (NotificationOutboxRepository.UpdateAsync) — ExecuteUpdate's row count was
discarded, so an operator Retry/Discard of a notification the retention purge had
already deleted reported success (the pre-ExecuteUpdate code threw
DbUpdateConcurrencyException). UpdateAsync now returns whether a row matched; the
operator one-shots answer "notification not found" and emit no audit row for the
action that did not happen, while the dispatcher logs a warning (its delivery
already happened; nothing to retry). GetByIdAsync switched to AsNoTracking since
the write is out-of-band.
Tests: 5 new SQL-backed regressions (over-long Target rejected on both paths +
boundary round-trip; concurrent first-write and already-created-by-another-writer
upserts; vanished-row UpdateAsync), a token-identity pin on the ingest fallback,
a repository-concurrency detector for the SiteCallAudit passes, and vanished-row
operator-path tests. The F1/F2/F4 regressions were each confirmed failing against
the pre-fix code. Suites: ConfigurationDatabase 369, AuditLog 378, SiteCallAudit
66, NotificationOutbox 152 — all green, solution builds with 0 warnings.
Joseph Doherty