Task 2 review follow-up. The plan specified MqttEquipmentTagParser.TryParse(reference)
with def.Name = the TagConfig blob, and told us to mirror a type named
ModbusEquipmentTagParser. Both are plan defects:
- EquipmentTagRefResolver documents that a v3 driver reference "is now always a
RawPath" and that the blob-parse fallback is retired. Keying Name by the blob
would make OnDataChange publish under a reference that never matches the
RawPath-keyed fan-out in DriverHostActor - silently dead in production with
every unit test still green.
- ModbusEquipmentTagParser does not exist. The six sibling drivers all use
<Driver>TagDefinitionFactory.FromTagConfig(tagConfig, rawPath, out def).
Changes:
- Rename MqttEquipmentTagParser -> MqttTagDefinitionFactory; TryParse(reference,
out def) -> FromTagConfig(tagConfig, rawPath, out def) setting Name: rawPath,
matching ModbusTagDefinitionFactory's structure, param docs and guard order.
- Pin the identity contract with a dedicated test so a regression to blob-keying
goes red.
- Read qos with the same strictness as the enums: a present-but-invalid qos
("high" / 1.5 / 5 / null) now rejects the tag and is warned by Inspect,
instead of being silently absorbed into the driver-level default and handing
the operator a weaker delivery guarantee than the one they authored.
- No ToTagConfig inverse: the siblings carry one solely for their Driver.<X>.Cli
project, the MQTT plan defines none, and the AdminUI editor template
references no driver factory. Recorded as an explicit YAGNI call in the type
doc rather than added speculatively.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Code-review Minor: the record typed ParameterNames/Parameters/Members/
SelectedColumns as IReadOnlyList<T> but was handed the planner's live List<T>
instances. SqlQueryPlan documents itself as safe to hold for plan caching, so
an aliased list is a real hazard once the reader starts reusing plans across
polls: IReadOnlyList<T> is downcastable, and one mutation would corrupt every
subsequent poll served by that plan.
Copying at the record boundary fixes it for every call site at once rather
than relying on each planner branch remembering to call AsReadOnly.
Pinned by a test that mutates the caller's lists after construction; verified
load-bearing (reverting the record turns it red).
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Executes a poll pass: resolve refs -> SqlGroupPlanner.Plan -> one command per
group -> slice the result set back to per-tag DataValueSnapshots, positionally
aligned with the caller's reference list (design §3.2).
The frozen-peer contract (design §8.3, the R2-01 S7 lesson) is the core of it.
CommandTimeout is only the server-side backstop; the client-side bound is a
linked CancelAfter PLUS Task.WaitAsync, because a linked token bounds only a
provider that honours it and ADO.NET providers vary. The whole per-group
operation — waiting for a concurrency slot, OpenAsync, and the query — runs off
one operationTimeout budget, so ReadAsync returns on time regardless of what the
database is doing. A breach Bad-codes that group (BadTimeout); caller
cancellation propagates instead, since nobody consumes a torn-down poll.
Also: absent row (BadNoData) stays distinct from a NULL cell (Uncertain, or Bad
under nullIsBad); duplicate plan members are all fed (two tags on one keyValue
bind one parameter but stay two members); the concurrency slot is released by the
work, not the waiter, so a frozen database can never hold more than
maxConcurrentGroups connections; the whole call throws only when the connection
itself cannot open, which is what earns PollGroupEngine's backoff.
SqlStatusCodes is driver-local, matching every sibling driver's own table — there
is no shared helper in Core.Abstractions and drivers do not reference the OPC UA
SDK. Values were read off Opc.Ua.StatusCodes rather than copied from a sibling,
because two of those tables carry transcription errors.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Three findings from the code review of the dialect seam:
- QuoteIdentifier used char.IsControl, which only covers Unicode category Cc.
Bidi overrides, zero-width spaces, soft hyphen and BOM are category Cf and
passed through untouched. They cannot escape the brackets, so this is not an
injection bypass — but the method rejects control characters precisely to
protect the integrity of logged/audited statements, and Cf characters spoof
rendered text while comparing byte-different from the real catalog name
(Trojan Source, CVE-2021-42574). Same rule, same rationale, wider category.
- The XML docs on both files asserted that identifiers 'are sourced only from
catalog-validated (INFORMATION_SCHEMA) names' and that rejection is 'a
backstop, not the primary defence'. Neither is true yet: design §8.1 does
specify that gate, but nothing implements it and no task in the plan
schedules one, so an authored TagConfig table/column reaches QuoteIdentifier
unfiltered. The docs now say so, because under-scrutinising this method on
the strength of a filter that does not exist is exactly the failure mode.
- The control-character test only pinned NUL, so a regression to a
Contains('\0') check would still have passed. Pinned the whole Cc category
plus the new Cf rule; verified load-bearing by deleting the guard and
observing exactly the 5 new cases go red.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Code review of f22db5d8 (approved-with-findings): the existing round-trip
tests only exercised explicit JSON payloads, so nothing failed if UseTls /
AllowUntrustedServerCertificate or the §5.1 numeric defaults were flipped.
Adds a defaults-pinning test plus a partial-JSON test that omits the TLS
knobs entirely (the production case — an operator config that just doesn't
mention TLS must not silently land insecure).
Also overrides the record's PrintMembers so ToString() no longer prints
Password in plaintext (verified RED before the fix: the new test failed
with the raw password in the rendered string). OpcUaClientDriverOptions has
the same unredacted-ToString() shape but is out of scope for this task per
the coordinator's note; flagging as a possible follow-up.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
The dialect owns the two things ADO.NET's System.Data.Common base types
cannot abstract: identifier quoting and the metadata-catalog SQL. It is
the driver's SQL-injection boundary — values always bind as DbParameters,
identifiers cannot, so the few that reach a command text are catalog-
sourced and pass through QuoteIdentifier.
QuoteIdentifier brackets one identifier part and doubles embedded ] (the
only metacharacter that can terminate a bracketed identifier early);
rejects null/empty/whitespace, >128 chars (T-SQL sysname ceiling), and any
control character (incl. NUL) as ArgumentException, without echoing the
untrusted value into the message. MapColumnType folds the design §3.7
families case-insensitively and never throws — an unrecognised family
falls back to String so a browse over an exotic column still renders;
timestamp/rowversion and time are deliberately NOT mapped to DateTime.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Per-plan copy-paste command (subagent-driven-development in a git worktree),
plus the slash-command and executing-plans/resume alternatives, and a note that
the four independent plans can run in concurrent worktrees.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
ClusterPrimaryHealthCheck was written three days' worth of debugging ago because
the shared ActiveNodeHealthCheck selected by RoleLeader and reported Healthy for
any node lacking the role. Health 0.3.0 fixes the shared check — oldest Up
member, role-preference scoping, Unhealthy when the node owns no active work —
so the private copy is now duplication rather than a workaround, and it is
deleted.
RolePreference [admin, driver] reproduces exactly what it did: a fused central
node answers for admin (where the singletons and the AdminUI are pinned), a
driver-only site node answers for driver.
SelectOldestUpMemberOfRole now delegates to the shared ClusterActiveNode instead
of re-implementing the age ordering. This is the point of the change rather than
a tidy-up: the redundancy snapshot drives the OPC UA ServiceLevel 250/240 split
while the health tier drives Traefik's admin routing, so two copies of "oldest Up
member of a role" would be two chances to advertise one node as authoritative
while gating the data plane on another. ControlPlane takes a ZB.MOM.WW.Health.Akka
reference for it; the layering trade-off is recorded at the PackageReference.
Behaviour note: a node carrying neither admin nor driver now answers 503 on the
active tier instead of 200. That case is reachable — RoleParser admits dev-only
and cluster-role-only nodes — and 503 is correct, since such a node owns no
active work and must not be in an active-tier pool. No docker-dev node is
affected: every rig node is admin+driver or driver-only.
Tests replaced in kind. The rule itself is now pinned in the library against a
real two-node cluster; what stays OtOpcUa's own decision is the wiring, so
ActiveTierRegistrationTests pins which check is on the active tag, that it is
registered on driver-only nodes too, and that it is not on the ready tier.
Verified: Host.Tests 25/25, ControlPlane redundancy 15/15.
Add a living progress tracker (docs/plans/2026-07-24-driver-expansion-tracking.md)
for the driver-expansion program's Waves 0-2, linked from the program design doc's
document map. One row per deliverable pointing at design + implementation plan + status.
Add executable implementation plans (plan .md + co-located .tasks.json) for the four
Wave 1/2 drivers, each authored by writing-plans methodology off its design doc and
mirroring the relevant existing driver:
- Modbus RTU 11 tasks (extends Driver.Modbus; RTU-over-TCP, direct-serial descoped)
- SQL poll 22 tasks (ISqlDialect seam, SQL Server only in v1; SQLite + central-SQL fixtures)
- MTConnect Agent 23 tasks (browse free via Wave-0 seam; TrakHound-vs-hand-rolled = Task 0)
- MQTT/Sparkplug B 27 tasks (P1 plain MQTT 0-14 then P2 Sparkplug 15-26; MQTTnet-5 pinning spike = Task 0)
Wave 0 (universal browser) remains merged (056887d6) with its live gate open (#468).
All four new plans are design-only -> plan-ready; nothing built yet.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Closes the remaining half of #494, and corrects the half fixed in 8dd9da7d.
The shared ActiveNodeHealthCheck(role: "admin") answered the wrong question twice
over. It returns Healthy for any node LACKING the role, so all four driver-only
site nodes called themselves active and no consumer could find the Primary of a
site Cluster. And it selects by RoleLeader - the lowest-ADDRESSED member - which
is not where Akka places singletons.
Replaced with ClusterPrimaryHealthCheck ("cluster-primary"). One rule: this node
is active iff it is the OLDEST Up member carrying its own active role, where the
active role is admin when the node has it and driver otherwise. That serves both
consumers correctly - a fused admin node answers for admin, so Traefik pins the
AdminUI to the node hosting the singletons; a driver-only site node answers for
driver, which is exactly SelectDriverPrimary, the same election behind
IsDriverPrimary and the OPC UA ServiceLevel 250/240 split. Per-mesh scoping is
free after Phase 6: ClusterState.Members already contains only this node's own
Cluster.
SelectDriverPrimary is generalised to SelectOldestUpMemberOfRole so the
age-ordering rule has one implementation. Two copies of "oldest Up member of a
role" would be two chances to silently disagree about who is in charge, and the
tier and the redundancy snapshot must never disagree.
THE ROLE-LEADER HALF MATTERED IN PRACTICE, not just in theory. On the rebuilt rig
the two orderings diverge right now:
akka leader (lowest address) = central-1
oldest admin member = central-2 <- hosts the singletons
8dd9da7d made the tier a real 503 but still selected by RoleLeader, so it would
have pinned Traefik to central-1 - the node NOT hosting the work. With this change
Traefik correctly routes to central-2.
Live-verified, exactly one 200 per mesh:
MAIN central-2 200 central-1 503 traefik: central-2 UP, central-1 DOWN
SITE-A site-a-1 200 site-a-2 503
SITE-B site-b-1 200 site-b-2 503
Tests: role-selection matrix and the startup-safe Degraded path in Host.Tests
(26 pass); parity between the tier's selector and the redundancy snapshot's, plus
role scoping, added to RedundancyPrimaryElectionTests, which forms a real two-node
cluster deliberately built so the oldest member is not the lowest-addressed one
(5 pass).
0.2.1 makes the shared ActiveNodeHealthCheck return Unhealthy (503), not
Degraded (200), for a node that carries the role but is not the role leader.
That is what the shared health spec always specified, what docs/ServiceHosting.md,
docs/v2/Architecture-v2.md and the 2026-05-26 alignment design all describe
("200 only on the Admin-role leader; 503 elsewhere"), and what
docker-dev/traefik-dynamic.yml + scripts/install/traefik-dynamic.yml assume when
they use /health/active as the load-balancer probe.
The implementation returned Degraded, which MapZbHealth maps to 200, so BOTH
central nodes always passed the probe and Traefik load-balanced the admin UI
across the pair instead of pinning it to the leader. The docs were right; the
code was wrong. Closes the Traefik half of #494.
No OtOpcUa code change — package pin only.
Live-verified on docker-dev, with the MAIN pair genuinely formed (memberCount 2,
both members naming one leader):
central-1 (leader) /health/active -> 200 traefik UP
central-2 (standby) /health/active -> 503 traefik DOWN
Failover drill (README step 2), which had never actually exercised anything:
stopping central-1 flipped Traefik to central-2 within 20 s and
http://localhost:9200/ answered 200 continuously across the swap — no outage.
Restarting central-1 reclaimed the role-leader and Traefik flipped back.
README corrected on two counts: the drill now states that exactly ONE backend is
UP by design, and step 3 no longer claims central-2 keeps leadership — RoleLeader
is the lowest-address member, so central-1 deterministically reclaims it. Added
the cold-boot caveat that starting both nodes at once can leave each self-forming
a 1-member cluster, in which case both are their own leader and both answer 200.
STILL OPEN in #494: driver-only nodes. The check is scoped to the admin role and
returns Healthy for any node that lacks it, so all four site nodes answer 200 and
the real per-Cluster redundancy Primary (oldest Up driver member, IsDriverPrimary)
is still not what this tier reports.
Picks up the additive per-entry `data` object in the canonical health JSON and
the cluster-view data the shared AkkaClusterHealthCheck now publishes (leader /
selfAddress / selfRoles / memberCount / unreachableCount).
No OtOpcUa code change is needed: the "akka" ready/active check is already the
shared ZB.MOM.WW.Health.Akka.AkkaClusterHealthCheck (Health/HealthEndpoints.cs),
so /health/ready starts carrying entries["akka"].data.leader on the bump alone.
Payloads from every other check are byte-identical — data is emitted only when a
check publishes some.
Prereq for the family overview dashboard (scadaproj
docs/plans/2026-07-22-overview-dashboard-impl-plan.md, Phase 2).
Verified: Host 21/21, AdminUI 692/692, Host builds 0 warnings.
Live rig check (admin node serves data.leader) deferred to the dashboard's
acceptance run.
The simultaneous-cold-start split-brain, carried as a Phase 7 "candidate follow-up,
not shipped", is now closed by the opt-in Cluster:BootstrapGuard (279d1d0f). Documents
the guard in CLAUDE.md's bootstrap section and marks the Phase 7 finding closed.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Closes the residual Phase-7 gap: when BOTH nodes of a 2-node pair cold-start at the
same instant, each self-first seed runs FirstSeedNodeProcess, times out waiting for
the other, and forms its own 1-node cluster — two Primaries in one pair (the Phase 6
live gate reproduced this reliably on docker). The prior mitigation was operational
(staggered start / compose depends_on), which does not exist on production hardware.
The guard (dark switch Cluster:BootstrapGuard:Enabled, default OFF) prevents the split
without giving up cold-start-alone:
- The lower-address node is the preferred founder: self-first, forms immediately.
- The higher node probes its partner's Akka port (TCP connect) up to PartnerProbeSeconds:
reachable => peer-first (join the founder, never race it); unreachable => self-first
(partner is dead, form alone). The order is decided BEFORE the single JoinSeedNodes,
from an explicit reachability signal — never re-formed mid-handshake (the retired
SelfFormAfter failure mode). When on, Akka gets no config seeds (BuildClusterOptions)
and ClusterBootstrapCoordinator drives the join.
Review-driven hardening: case-insensitive tie-break (a hostname-casing mismatch would
reopen the split); fail-fast validation of the timing knobs; the residual "founder dies
in the probe->join window" hang is documented and made operator-visible (warning + a
restart recovers). Real-ActorSystem coordinator tests cover the load-bearing higher-node
cold-start-alone case; 147/147 Cluster tests pass.
Live-gated on docker-dev (site-a = enablement demo, serialization removed, guard on;
site-b keeps depends_on-serialization + guard off as the A/B control): simultaneous
start -> site-a-1 founds, site-a-2 probes-reachable-joins -> 250/240, NO split;
higher-node-alone -> probes dead founder, self-forms -> 250; founder rejoin -> 240.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
All 6 failover drills pass on the docker-dev three-mesh rig:
- D1 MAIN graceful manual-failover via the AdminUI "Trigger failover" button —
Primary leaves, peer→250, restarts and rejoins with no split.
- D2 SITE-A auto-down failover, both directions; D3 SITE-B crash-the-oldest.
- D4 auto-down 1-vs-1 survival — every survivor stayed Up (closes the gate
deferred since Phase 0a).
- D5 self-first cold-start-alone — a node boots with its partner down and forms
its own mesh (gate b).
- D6 recovery — restarted nodes rejoin as Secondary (240).
Ships a one-page co-located operator runbook (OtOpcUa + ScadaBridge on shared
site VMs). Manual-failover button confirmed MAIN-only by construction; site
pairs (driver-only, no UI) fail over via auto-down. Carried Phase-6 finding —
simultaneous cold-start of both pair VMs can split — mitigated operationally in
the runbook (staggered start); a product-level join guard is a candidate
follow-up, not shipped.
The per-cluster mesh program (Phases 0a–7) is COMPLETE.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
The cluster-redundancy singleton's role scope is computed at AddAkka-configurator
time and must come from AkkaClusterOptions, never by resolving IClusterRoleInfo
there (it depends on the ActorSystem being built → stack overflow at boot). Caught
by the Phase 6 live gate; fixed in 3a4ed8dd.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Records the full live-gate run against master on the docker-dev three-mesh rig.
All 8 legs pass: three isolated 2-node meshes, one Primary per pair (250/240),
deploy sealed acks=6 over per-cluster ClusterClient, telemetry gRPC :4056 up +
reconnect, reconciler own-cluster-scoped, secrets pair-local, split validator
refuses Dps, and per-pair failover with auto-down 1-vs-1 survival (also closes the
deferred Phase 0a gate). Three defects were caught and fixed forward (3a4ed8dd,
792f28ec) — see the live-gate doc's Findings section. Task 9 marked completed.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Two docker-dev-only defects the Phase 6 live gate surfaced (both invisible to
`docker compose config`, which validates the file but never boots the app):
1. Driver-only site nodes crashed at boot with OptionsValidationException — LDAP
transport None + AllowInsecure false. Only central carried the Security__Ldap__*
block, but the site nodes serve OPC UA endpoints and validate LDAP options too, and
they override `environment` wholesale (YAML `<<:` doesn't deep-merge it). Extracted
the block to a shared &ldap-env anchor merged into every host node.
2. Site pairs split-brained at simultaneous startup (both nodes "JOINING itself",
250/250 instead of 250/240). Both are self-first seeds, so both run Akka's
FirstSeedNodeProcess; the partner didn't depend on its pair founder, so they raced
and each formed a 1-node cluster. Added an &akka-founder-healthcheck (bash /dev/tcp
probe of Akka 4053 — no nc/curl in the image) to site-a-1/site-b-1 and switched the
partners to depends_on service_healthy, so the founder forms first and the partner
JOINS it. (Carry the underlying simultaneous-cold-start property to Phase 7 — it is
inherent to symmetric self-first seeding, present for central since #459.)
Live gate record: docs/plans/2026-07-24-mesh-phase6-live-gate.md (legs 1-2 PASS —
three isolated meshes, one Primary per pair at 250/240).
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Phase 6 wired the re-homed redundancy singleton in Program.cs as
`WithOtOpcUaClusterRedundancySingleton(sp.GetRequiredService<IClusterRoleInfo>())`
inside the AddAkka configurator lambda. That lambda runs WHILE the ActorSystem is
being built, but ClusterRoleInfo depends on the ActorSystem (it is a live
Cluster.State view) — so resolving it there recurses into ActorSystem construction
and every node dies at boot with StackOverflowException. It compiles cleanly (a
runtime DI cycle) and RedundancyStateSingletonRehomeTests passed a hand-built
FakeClusterRoleInfo straight into the extension, mocking around the composition-root
line that overflows. The docker-dev live gate caught it on first boot.
Derive the singleton's cluster-role scope from AkkaClusterOptions (pure config, no
ActorSystem) instead: BuildClusterRedundancySingletonOptions / the extension now take
AkkaClusterOptions and compute Role = Roles.FirstOrDefault(IsClusterRole) ?? driver —
identical to ClusterRoleInfo.ClusterRole, which derives from the same config. Program.cs
passes IOptions<AkkaClusterOptions>.Value, which has no ActorSystem dependency.
Live-verified: rebuilt image boots with zero stack-overflow lines, cluster singletons
form per mesh. 5/5 rehome tests pass; Host builds clean.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Redundancy.md: KNOWN-LIMITATION (per-Akka-cluster election) marked RESOLVED;
new 'Per-cluster meshes (Phase 6)' section + pair-local secrets note; manual-
failover mesh-scope caveat removed; auto-down 1-vs-1 note updated (every mesh is
now two nodes, drill deferred to Phase 7). IManualFailoverService + ClusterRedundancy
razor caveats updated to pair-local reality. Configuration.md documents the
cluster-{ClusterId} role, per-pair self-first seeds, SplitTopologyTransportValidator,
and the intentional Dps default. Program + design status tables + CLAUDE.md marked
Phase 6 DONE.
(Task 8 subagent completed the edits but died on an API error before committing;
reviewed and committed by the controller.)
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Rewrite docker-dev/docker-compose.yml from one shared six-node gossip ring
into three self-contained pairs (MAIN: central-1/2, SITE-A: site-a-1/2,
SITE-B: site-b-1/2), all still on the ActorSystem name `otopcua` and the one
shared docker network — separation is purely by per-pair self-first
Cluster:SeedNodes, faithful to how production splits over a WAN rather than
a firewall.
Per node:
- Cluster__Roles / OTOPCUA_ROLES gain a `cluster-<ClusterId>` role
(cluster-MAIN / cluster-SITE-A / cluster-SITE-B), the marker
SplitTopologyTransportValidator and ClusterRoleInfo key off.
- Cluster__SeedNodes now lists only the node's own pair (self first, partner
second); site nodes no longer seed off central-1.
- MeshTransport__Mode default flips Dps -> ClusterClient (still overridable
via OTOPCUA_MESH_MODE) on all six nodes — SplitTopologyTransportValidator
now refuses to boot a cluster-role node left on Dps.
- Telemetry__Mode=Grpc added on all six driver nodes; TelemetryDial__Mode=Grpc
added on central-1/central-2 only (the admin pair).
- ConfigSource/ConfigServe modes and MeshTransport contact points are
unchanged (already split-correct since Phases 3/4/2).
seed-clusters.sql needed no changes — the ClusterNode rows already carry the
correct ClusterId/Host/AkkaPort/GrpcPort per node. Validated with
`docker compose -f docker-dev/docker-compose.yml config`.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty