Task 26 — the P2 milestone gate. Ran the live /run verification on an isolated
docker-dev rig (project otopcua-mqtt, ports 9210/4850-4851/14350, image built
from this branch) against the real Mosquitto TLS+auth broker and the C#
Sparkplug edge-node simulator on 10.100.0.35, and recorded the result.
The gate found three defects. Two are the same defect class the P1 gate found
twice — a hand-maintained AdminUI surface left behind by a driver-side feature —
and the third is a pre-existing cross-driver bug that only a Sparkplug flow
could surface.
1. CRITICAL, FIXED — MqttDriverForm still shipped its P1 Sparkplug PLACEHOLDER.
Switching Mode to SparkplugB rendered a "not available yet" notice and NO
Group ID field, so with Sparkplug ingest fully shipped there was still no
way to author a Sparkplug driver from the AdminUI at all. Sparkplug.GroupId
is the driver's entire subscription filter (spBv1.0/{GroupId}/#): blank ⇒
connected, Healthy, ingesting nothing. Now authors all five Sparkplug keys,
MERGES over the existing sub-object rather than replacing it (so a key a
newer driver adds inside it survives an older AdminUI), leaves it untouched
in Plain mode, and validates the group id as the topic segment it is.
Pinned by 8 MqttDriverFormModelTests cases, verified falsifiable — 8 RED
with the fix stubbed out.
2. PRE-EXISTING + CROSS-DRIVER, FIXED — every node label in the shared
DriverBrowseTree was an <a href="#">. In a Blazor Web App, blazor.web.js's
enhanced-navigation click interceptor resolves a bare "#" against
<base href="/">, so clicking ANY browse-tree node label navigated the whole
AdminUI to "/", tore down the circuit, and destroyed the hosting modal —
losing the browse session AND the tag selection. @onclick:preventDefault
does not help: it suppresses the browser's default action, not Blazor's own
interceptor. Labels are now <button type="button">. Dates to the component's
introduction (2026-05-28) and affects EVERY driver's picker; it surfaced
only now because choosing a rebirth scope is the first flow that requires
clicking a label rather than the ▶ toggle (always a button, always fine).
3. FIXED (mitigation) — the browse tree rendered exactly once, at open, and
never again, while OpenAsync returns as soon as the SUBSCRIBE is granted.
On Sparkplug that means it is almost always empty forever, because births
are never retained. Added a Refresh button that re-reads the root against
the SAME session (nothing reconnects, nothing observed is lost, the tag
selection is kept, only the armed rebirth scope is cleared).
Live gate result (all against the real broker + simulator, group OtOpcUaSim):
- driver authored end-to-end through the fixed MqttDriverForm; blob is
Mode:SparkplugB + Sparkplug.GroupId:OtOpcUaSim with enums as names
- browse: BROWSER OPEN chip, Sparkplug-only rebirth panel, tree renders
Group → EdgeNode → [Device] → Metric with the device folder Filler1 and
node-level metric leaves SIDE BY SIDE, and "Node Control/Rebirth" as ONE
leaf (the metric-name-is-not-a-topic-segment rule holding)
- rebirth: group scope names the group + the 32-node cap, Cancel published
NOTHING (simulator log unchanged); edge-node scope → "1 command published"
and the simulator logged "rebirth NCMD #1 received; republishing metadata";
group scope → "2 commands published", both edge nodes re-birthed; a device
and a metric both resolve UP to "edge node EdgeA"; the panel does NOT render
for a Plain MQTT device
- browse-commit wrote bindable tuples with no topic/address key —
{"groupId","edgeNodeId","metricName","deviceId"} for the device metric and
deviceId ABSENT (not blank) for the node-level one, datatypes inherited from
the birth (Int64 / Float)
- deployed (Sealed), and both nodes served live changing values through OPC UA
at the 2 s cadence — Good 0x00000000, no BadNodeIdUnknown
- death→STALE: stopping the simulator drove both nodes to 0x80000000 with an
empty value ~2 s later, and restarting it recovered them to Good on the new
birth (FillCount back to its birth-declared 1000, then counting)
- rediscovery fired exactly TWICE (once per authored scope: OtOpcUaSim/EdgeA
7 metrics, OtOpcUaSim/EdgeA/Filler1 3 metrics) and was then gated across
many subsequent births/rebirths — the anti-storm change gate working, and
EdgeB correctly filtered out as an unauthored scope
- tag editor: opens in SparkplugB (mode inference on reopen) with all four
descriptor fields populated; blank group → "A Sparkplug group ID is
required."; "Plant/1" rejected; "Node Control/Rebirth" ACCEPTED and saved
with the slash whole; dataType override persists and its key is ABSENT again
after selecting "(from birth certificate)"
Two things are NOT verified, and are recorded rather than claimed:
- Rediscovery is INERT in v3 and this is a platform gap, not an MQTT one:
nothing subscribes to IRediscoverable.OnRediscoveryNeeded and
DriverHostActor.HandleDiscoveredNodes hard-returns. A DBIRTH introducing a
metric does NOT change the OPC UA tree; redeploy. Verified from the driver's
log line only, exactly as far as it can be verified.
- A metric name containing "/" cannot be BROWSE-COMMITTED: the derived raw tag
Name is a RawPath segment and may not contain "/", so the spec-mandatory
"Node Control/Rebirth" is refused ("Row 3: Name must not contain '/'"). The
refusal is loud and all-or-nothing, never a silently mis-bound tag, and
Manual entry is the working path. Fixing it needs a name-sanitisation policy
with a collision answer, so it was recorded rather than guessed at.
Also left open + documented: an empty browse tree cannot arm a rebirth (the
scope comes from a tree click, and the session side already accepts a bare
{group}/{edgeNode} — only a UI path is missing); _canRebirth is captured at
browse-open; the tag editor injects the Plain-only payloadFormat key into a
Sparkplug blob (cosmetic — the factory routes on the tuple).
Suites: offline 1528 passed / 0 failed (581 Driver.Mqtt + 809 AdminUI + 138
Core.Abstractions); live 15/15 against the broker + simulator.
Docs: docs/drivers/Mqtt.md brought fully up to date for P2 (Sparkplug config
sub-object, both tag shapes, the ingest state machine, rediscovery, browse +
rebirth + Refresh, a Known-gaps table); Mqtt-Test-Fixture.md gains the simulator
and drops its "Sparkplug has no fixture" claims; infra/README.md §3 gains the
simulator row; CLAUDE.md gains the simulator endpoint facts; the tracking doc
marks MQTT/Sparkplug COMPLETE. docker-dev/docker-compose.mqtt.yml is the
isolated-rig overlay the gate ran on.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
OtOpcUa documentation
Two tiers of documentation live here:
- Current reference at the top level (
docs/*.md) — describes what's shipped today. Start here for operator + integrator reference. - Implementation history + design notes at
docs/v2/*.md— the authoritative plan + decision log the current reference is built from. Start here when you need the why behind an architectural choice, or when a top-level doc says "see plan.md § X".
The project was originally called LmxOpcUa (a single-driver Galaxy/MXAccess OPC UA server) and has since become OtOpcUa, a multi-driver OPC UA server platform. Any lingering LmxOpcUa-string in a path you see in docs is a deliberate residual (executable name lmxopcua-cli, client PKI folder {LocalAppData}/LmxOpcUaClient/) — fixing those requires migration shims + is tracked as follow-ups.
Platform overview
v2 (2026-05-26): the separate
OtOpcUa.Server+OtOpcUa.Adminservices fused into a single role-gatedOtOpcUa.Hostbinary, joined by an Akka.NET cluster. See v2 design for the architectural decision.
- Core owns shared abstractions (driver capability contracts, scripting, virtual tags, alarm historian).
- Drivers plug in via capability interfaces in
ZB.MOM.WW.OtOpcUa.Core.Abstractions:IDriver,IReadable,IWritable,ITagDiscovery,ISubscribable,IHostConnectivityProbe,IAlarmSource,IHistoryProvider,IPerCallHostResolver. Each driver opts into whichever it supports. - Host (
src/Server/ZB.MOM.WW.OtOpcUa.Host) is the single fused binary (.NET 10, AnyCPU).OTOPCUA_ROLESenv decides what to mount:admin(Blazor + control-plane singletons),driver(OPC UA endpoint + per-node actors), or both. See ServiceHosting.md. - Cluster + ControlPlane + Runtime + AdminUI + Security sit between Core and Host. The cluster glues per-node actors into one logical fleet; the control-plane singletons (deploy coordinator, audit writer, redundancy state) live on the admin role-leader. See Redundancy.md.
- The Galaxy driver still reaches MXAccess via gRPC to a separately-installed mxaccessgw sidecar (sibling repo).
Where to find what
Architecture + data-path reference
| Doc | Covers |
|---|---|
| OpcUaServer.md | Top-level server architecture — Core, driver dispatch, Config DB, generations |
| AddressSpace.md | GenericDriverNodeManager + ITagDiscovery + IAddressSpaceBuilder |
| ReadWriteOperations.md | OPC UA Read/Write → CapabilityInvoker → IReadable/IWritable |
| DriverLifecycle.md | Server-side driver lifecycle + infrastructure contracts (IDriverFactory, IDriverProbe, IDriverSupervisor, IDriverHealthPublisher, IDriverConfigEditor, IHistorianDataSource) + the Commons library |
| Subscriptions.md | Monitored items → ISubscribable + per-driver subscription refcount (v1 archive) |
| AlarmTracking.md | IAlarmSource + AlarmSurfaceInvoker + OPC UA alarm conditions — native Galaxy alarms end-to-end (live) |
| AlarmTracking.md | Original alarm-tracking write-up (v1 archive) |
| AlarmHistorian.md | Core.AlarmHistorian store-and-forward sink — LocalDbStoreAndForwardSink, the replicated alarm_sf_events buffer + Primary-only drain, IAlarmHistorianWriter, dead-letter/retry/eviction |
| DataTypeMapping.md | Per-driver DriverAttributeInfo → OPC UA variable types (v1 archive — live mapping is in src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Browse/DataTypeMap.cs) |
| IncrementalSync.md | Address-space rebuild on redeploy + sp_ComputeGenerationDiff |
| HistoricalDataAccess.md | IHistoryProvider as a per-driver optional capability (v1 archive) |
| VirtualTags.md | Core.Scripting + Core.VirtualTags — Roslyn script sandbox, engine, dispatch alongside driver tags |
| ScriptEditor.md | Monaco script editor — Roslyn-backed IntelliSense (completions, diagnostics, hover, tag-path) for C# virtual-tag scripts; AdminUI/ScriptAnalysis/ backend |
| ScriptedAlarms.md | Core.ScriptedAlarms — script-predicate IAlarmSource + Part 9 state machine |
One Core subsystem is shipped without a dedicated top-level doc; see the section in the linked doc:
| Project | See |
|---|---|
Analyzers (Roslyn OTOPCUA0001) |
security.md § OTOPCUA0001 Analyzer |
Drivers
| Doc | Covers |
|---|---|
| drivers/README.md | Index of the eight shipped drivers + capability matrix |
| drivers/Galaxy.md | Galaxy driver — in-process gRPC client to the mxaccessgw sidecar |
| v1/drivers/Galaxy-Repository.md | Galaxy-specific discovery via the ZB SQL database (v1 archive — the gateway owns this path now) |
For Modbus / S7 / AB CIP / AB Legacy / TwinCAT / FOCAS / OPC UA Client specifics, see v2/driver-specs.md.
Operational
| Doc | Covers |
|---|---|
| Configuration.md | Live appsettings + environment-variable reference (current state) |
| Configuration.md | appsettings bootstrap + Config DB + Admin UI draft/publish (v1 archive — OTOPCUA_GALAXY_* env vars now live in mxaccessgw config) |
| Uns.md | The global /uns master tree — manage Area/Line/Equipment/Tag/VirtualTag fleet-wide; replaces the per-cluster UNS/Equipment/Tags tabs |
| security.md | Transport security profiles, LDAP auth, ACL trie, role grants, OTOPCUA0001 analyzer |
| Redundancy.md | RedundancyCoordinator, ServiceLevelCalculator, apply-lease, Prometheus metrics |
| Reservations.md | Fleet-wide ZTag / SAPID external-ID reservations — publish-time claim, release flow |
| ServiceHosting.md | Single fused OtOpcUa.Host binary install/uninstall with OTOPCUA_ROLES gating; the historian backend is the external HistorianGateway |
| StatusDashboard.md | Pointer — superseded by v2/admin-ui.md |
Client tooling
| Doc | Covers |
|---|---|
| Client.CLI.md | otopcua-cli — OPC UA command-line client |
| Client.UI.md | Avalonia desktop client |
| DriverClis.md | Driver test-client CLIs — index + shared commands |
| Driver.Modbus.Cli.md | otopcua-modbus-cli — Modbus-TCP |
| Driver.AbCip.Cli.md | otopcua-abcip-cli — ControlLogix / CompactLogix / Micro800 / GuardLogix |
| Driver.AbLegacy.Cli.md | otopcua-ablegacy-cli — SLC / MicroLogix / PLC-5 (PCCC) |
| Driver.S7.Cli.md | otopcua-s7-cli — Siemens S7-300 / S7-400 / S7-1200 / S7-1500 |
| Driver.TwinCAT.Cli.md | otopcua-twincat-cli — Beckhoff TwinCAT 2/3 ADS |
| Driver.FOCAS.Cli.md | otopcua-focas-cli — Fanuc FOCAS/2 CNC |
Requirements
| Doc | Covers |
|---|---|
| reqs/HighLevelReqs.md | HLRs — numbered system-level requirements |
| reqs/OpcUaServerReqs.md | OPC UA server-layer reqs |
| v1/reqs/ServiceHostReqs.md | Per-process hosting reqs (v1 archive — only OtOpcUa server hosting remains in scope post-PR-7.2) |
| reqs/ClientRequirements.md | Client CLI + UI reqs |
| v1/reqs/GalaxyRepositoryReqs.md | Galaxy-scoped repository reqs (v1 archive — owned by mxaccessgw today) |
| v1/reqs/MxAccessClientReqs.md | Galaxy-scoped MXAccess reqs (v1 archive — owned by mxaccessgw today) |
| reqs/StatusDashboardReqs.md | Pointer — superseded by Admin UI |
Implementation history (docs/v2/)
Design decisions + phase plans + execution notes. Load-bearing cross-references from the top-level docs:
- v2/plan.md — authoritative v2 vision doc + numbered decision log (referenced as "decision #N" elsewhere)
- v2/admin-ui.md — Admin UI spec
- v2/acl-design.md — data-plane ACL + permission-trie design (Phase 6.2)
- v2/config-db-schema.md — Config DB schema reference
- v2/driver-specs.md — per-driver addressing + quirks for every shipped protocol
- v2/dev-environment.md — dev-box bootstrap
- v2/test-data-sources.md — integration-test simulator matrix (includes the pinned libplctag
ab_serverversion for AB CIP tests) - v2/multi-host-dispatch.md — per-PLC circuit breakers (Phase 6.1 decision #144)
- v2/v2-release-readiness.md — release-readiness tracker
- v2/phase-7-status.md — Phase 7 reconciliation: what shipped vs. the plan, and the five remaining gaps
- v2/implementation/phase--.md — per-phase execution plans with exit-gate evidence
v1 archive
The v1 in-process MXAccess architecture (Galaxy.Host + Galaxy.Proxy + Galaxy.Shared, .NET 4.8 x86 COM, the OtOpcUaGalaxyHost Windows service) was retired in PR 7.2 (2026-04-30, commit ae7106d). Docs that described that shape are kept under v1/ as historical record — see v1/README.md for the index.