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lmxopcua/docs/plans/2026-07-20-localdb-adoption-phase2.md.tasks.json
T
Joseph Doherty f9f1b8fcee fix(localdb): phase-2 live gate — 4 production defects found and fixed
Gate record: docs/plans/2026-07-20-localdb-phase2-live-gate.md.
Checks 1, 2, 5, 6 pass. Checks 3 and 4 are NOT satisfied — the defect they
were meant to confirm turned out to be the opposite of what the plan assumed.

Three defects crash-looped every driver node before check 1 could even run:

1. An empty ServerHistorian:ApiKey kills the host. ServerHistorianOptions-
   Validator exists to turn exactly that class of failure into a named
   OptionsValidationException, but its documented fail tier explicitly excluded
   ApiKey on the reasoning that a keyless client "degrades — the gateway rejects
   calls". It does not: the client validates its own options at construction, so
   the process dies during Akka startup and never makes a call.

2. UseTls disagreeing with the endpoint scheme kills the host too, in both
   directions (both messages confirmed in the shipped client assembly). Moving an
   endpoint from https to http without clearing UseTls is an ordinary migration
   slip.

3. Plaintext h2c was UNREACHABLE. HistorianGatewayClientAdapter forwarded the
   TLS-only options unconditionally, and AllowUntrustedServerCertificate defaults
   to false, so it always sent RequireCertificateValidation=true — which the
   client rejects outright when UseTls=false. Every http:// deployment crashed,
   though the scheme is documented as the supported way to select h2c, and the
   only workaround was to assert a certificate posture for a connection that has
   no certificate.

The fourth was the blocker, and it is Phase 2's own:

4. The drain gate deferred to a Primary that cannot deliver. Redundancy roles are
   elected CLUSTER-WIDE; the alarm queue is PAIR-LOCAL. On the rig the elected
   driver Primary is central-1 — it carries the driver Akka role, replicates
   nobody's LocalDb and does not even run the alarm historian — so every driver
   node logged "Historian drain suspended", including the two site-b nodes that
   have no peer at all. Nothing drained anywhere, where before Phase 2 it drained
   fine. The cost is not a duplicate; it is the buffer growing to the capacity
   wall and evicting the audit trail it exists to protect.

   Fixed in three layers: a separate ShouldDrainAlarmHistory policy (unknown role
   drains; the two gates now deliberately disagree, and a test pins that); peer-
   host matching in DriverHostActor so a node stands down only for a Primary
   holding its rows; and AddAlarmHistorian short-circuiting the gate when
   replication is unconfigured — testing BOTH Replication:PeerAddress and
   SyncListenPort, since only the dialing half sets the former while both halves
   share the queue.

   Every one of these follows from the asymmetry: a false allow costs a duplicate
   row, which at-least-once delivery already accepts and payload-hash ids
   collapse; a false deny loses data silently.

A third vacuous test, caught by the same delete-the-guard discipline: the
role-view tests stayed green with the guard removed, because AwaitAssert polls
until an assertion passes and the assertion was "reads open" — which is the
SEEDED value, satisfied at the first poll before the actor processed anything.
They now assert the sequence of published values through a recording view; the
control then goes red for exactly the cases that matter.

Migration evidence: 11 legacy rows across two deliberately overlapping files
converged to exactly 9 identical rows on both nodes, proving D-6's payload-hash
identity on real nodes rather than in a fixture.

Open design fork, recorded in the gate doc rather than decided here: a pair
cannot currently identify its own Primary, so both halves drain. Safe in every
topology — nothing loses data — but the gate's de-duplication benefit is
unrealised until roles are scoped per pair.

Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
2026-07-21 06:13:01 -04:00

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{
"planPath": "docs/plans/2026-07-20-localdb-adoption-phase2.md",
"tasks": [
{
"id": 0,
"subject": "Task 0: Recon \u2014 sink schema, seam, drain lifecycle, role-view bridge (STOP conditions)",
"status": "completed",
"note": "STOP condition does NOT fire (no BLOB; PayloadJson TEXT). Recon doc: docs/plans/2026-07-20-localdb-phase2-recon.md. Key finding: the drain worker is an internal Timer inside the sink (not a hosted service/actor), so the gate is a Func<bool> ctor param; and HistorianAdapterActor already primary-gates ENQUEUE with a different policy (ShouldHistorize) - which is why today's ungated drain is safe and why replication breaks it. Deviations D-1..D-4 recorded."
},
{
"id": 1,
"subject": "Task 1: alarm_sf_events schema + registration (+ exact-set pin update)",
"status": "completed",
"blockedBy": [
0
],
"note": "alarm_sf_events created in AlarmSfSchema (Core.AlarmHistorian) + registered third in LocalDbSetup.OnReady. Exact-set pin updated to 3 tables. DEVIATION D-5: kept the legacy delete-on-ack + dead_lettered flag + last_error rather than the plan's status column (no sweeper for 'delivered' rows; last_error is the only record of why a row died). Drain ORDER BY moves to (enqueued_at_utc, id)."
},
{
"id": 2,
"subject": "Task 2: Rewire sink onto ILocalDb + delete bespoke file management (cutover 1/2)",
"status": "completed",
"blockedBy": [
1
],
"note": "Sink rewritten as LocalDbStoreAndForwardSink over ILocalDb; bespoke file/pragma/schema management deleted with the old class. AlarmHistorian:DatabasePath removed (breaking config key). Ids are a deterministic payload hash (D-1), not GUIDs."
},
{
"id": 3,
"subject": "Task 3: Primary-gated drain via PrimaryGatePolicy (cutover 2/2 \u2014 may co-commit with Task 2)",
"status": "completed",
"blockedBy": [
2
],
"note": "Drain gated on IRedundancyRoleView, a singleton DriverHostActor publishes PrimaryGatePolicy's verdict to on every snapshot. Fails closed on a throwing gate; seeded OPEN so a non-redundant deployment is never silently stopped. New HistorianDrainState.NotPrimary + transition-logged (D-2). Landed with Task 2 as one commit (D-3)."
},
{
"id": 4,
"subject": "Task 4: One-time alarm-historian.db legacy migrator",
"status": "completed",
"blockedBy": [
3
],
"note": "AlarmSfLegacyMigrator runs LAST in OnReady (which now takes IConfiguration - no skip-migration overload exists). DEVIATION D-6: ids are the payload hash (AlarmSfSchema.DeriveId, lifted out of the sink) rather than mig-{node}-{legacyId} - a warm pair's two legacy files OVERLAP, and node-prefixing would carry that duplication forward forever. DEVIATION: tests live in Host.IntegrationTests; the plan's Host.Tests project does not exist."
},
{
"id": 5,
"subject": "Task 5: Convergence + failover scenarios in the pair harness (+ positive control)",
"status": "completed",
"blockedBy": [
3
],
"note": "4 scenarios green. POSITIVE CONTROL RUN (RegisterReplicated(alarm_sf_events) commented out): 3/4 went red immediately; the 4th (same-event-on-both-nodes) passed VACUOUSLY - with replication off each node trivially held its own single row. Strengthened by enqueuing a second distinct event on B and asserting BOTH nodes hold 2; it then went red under the control too. Control restored, all 4 green. Also fixed a SECOND exact-set pin the plan predicted: LocalDbWiringTests."
},
{
"id": 6,
"subject": "Task 6: Rig config + docs",
"status": "completed",
"blockedBy": [
3
],
"note": "Rig: AlarmHistorian__Enabled=true on site-a-1/2 AND site-b-1/2, with MaxAttempts raised to 1e6 (D-4: the default 10 would dead-letter the queue ~5min into the rig's permanent gateway outage) and a deliberately unresolvable ServerHistorian__Endpoint. NOTE: the endpoint is REQUIRED - ServerHistorianOptionsValidator is consumer-gated on AlarmHistorian:Enabled, so an empty one fails host start. Docs: runbook, AlarmHistorian.md, AlarmTracking.md, Configuration.md, Redundancy.md, docs/README.md, CLAUDE.md."
},
{
"id": 7,
"subject": "Task 7: DoD sweep (offline) \u2014 STOP and report after this",
"status": "completed",
"blockedBy": [
4,
5,
6
],
"note": "Build: 0 errors solution-wide; 0 warnings from every project this branch touches (the ~816 solution-wide warnings are pre-existing xUnit1051/OTOPCUA0001/CS86xx in untouched driver + client test projects). GREPS FOUND REAL DRIFT Task 6 missed: 8 live sites still named the deleted SqliteStoreAndForwardSink - CLAUDE.md, the AdminUI /alarms/historian panel text (user-visible), HistorianAdapterActor (a <see cref> that did NOT warn), Runtime + Host + 2 Driver.Historian.Gateway doc comments, 1 gateway test comment, docs/drivers/Historian.Wonderware.md; plus docs/AlarmTracking.md still claimed a Validate() startup warning for a relative DatabasePath (that branch is gone). All fixed. Code refs to AlarmHistorian:DatabasePath now reduce to exactly two intentional ones: AlarmSfLegacyMigrator.LegacyPathKey and its test. No 'new SqliteConnection' in Core.AlarmHistorian. Both exact-set pins assert the 3-table set, both directions. Guard-deletion evidence (both vacuous passes + the pin inventory) consolidated into the recon doc."
},
{
"id": 8,
"subject": "Task 8: Live gate on the docker-dev rig (needs explicit user go-ahead)",
"status": "completed",
"blockedBy": [
7
],
"note": "Gate doc: docs/plans/2026-07-20-localdb-phase2-live-gate.md. Checks 1/2/5/6 PASS; checks 3+4 NOT SATISFIED (see below). FOUR production defects found + fixed, three of which crash-looped every driver node before check 1 could run: (1) empty ServerHistorian:ApiKey crashes the host - the validator had explicitly classified it as 'degrades', which is false because the gateway client validates its own options at construction; (2) UseTls vs endpoint scheme mismatch crashes likewise, both directions; (3) plaintext h2c was UNREACHABLE - the adapter forwarded TLS-only options unconditionally so every documented http:// deployment crashed; (4) THE BLOCKER - the drain gate deferred to a CLUSTER-WIDE elected Primary while the queue is PAIR-LOCAL. On the rig that Primary is central-1 (carries the driver Akka role, replicates nobody, runs no historian), so ALL FOUR driver nodes suspended their drains including unpaired site-b: silent permanent loss where pre-Phase-2 drained fine. Fixed in 3 layers (separate ShouldDrainAlarmHistory policy; peer-host matching in DriverHostActor; gate short-circuited entirely when replication is unconfigured, testing BOTH PeerAddress and SyncListenPort since only the dialer sets the former). Also fixed a THIRD vacuous test: AwaitAssert on the seeded-open value passed with the guard deleted; now asserts the sequence of PUBLISHED values via a recording view. Migration evidence: 11 legacy rows across two overlapping files -> exactly 9 identical rows on both nodes, proving D-6's payload-hash identity live. OPEN DESIGN FORK (in the gate doc): a pair cannot identify its own Primary, so both halves drain - safe (no loss, duplicates only) but the gate's de-dup benefit is unrealised."
}
],
"lastUpdated": "2026-07-21T00:00:00Z"
}