All four `High` + `Medium` items flagged as OPEN at the 2026-04-18 exit gate closed in PR 4
(`caa9cb8 Phase 2 PR 4 — close the 4 open high/medium MXAccess findings from
exit-gate-phase-2-final.md`):
| ID | Finding | Resolution |
|----|---------|------------|
| High 1 | MxAccess Read subscription-leak on cancellation | One-shot read now wraps subscribe → first `OnDataChange` → unsubscribe in try/finally. Per-tag callback always detached. If the read installed the underlying subscription (prior `_addressToHandle` key was absent) it tears it down on the way out — no leaked probe item handles on caller cancel or timeout. |
| High 2 | No MXAccess reconnect loop, only supervisor-driven recycle | `MxAccessClient` gains `MxAccessClientOptions { AutoReconnect, MonitorInterval=5s, StaleThreshold=60s }` + a background `MonitorLoopAsync` started on first `ConnectAsync`. Checks `_lastObservedActivityUtc` each interval (bumped by every `OnDataChange` callback); if stale, probes the proxy with a no-op COM `AddItem("$Heartbeat")` on the StaPump; on probe failure does reconnect-with-replay — Unregister (best-effort), Register, snapshot `_addressToHandle.Keys`, clear, re-AddItem every previously-active subscription. `ConnectionStateChanged` fires on the false→true transition; `ReconnectCount` bumps. |
| Medium 3 | `SubscribeAsync` doesn't push `OnDataChange` frames yet | `IGalaxyBackend` gains `OnDataChange` / `OnAlarmEvent` / `OnHostStatusChanged` events. New `IFrameHandler.AttachConnection(FrameWriter)` called per-connection by `PipeServer` after Hello. `GalaxyFrameHandler.ConnectionSink` subscribes the events for the connection lifetime, fire-and-forgets pushes as `MessageKind.OnDataChangeNotification` / `AlarmEvent` / `RuntimeStatusChange` frames through the writer, swallows `ObjectDisposedException` for dispose race, unsubscribes on Dispose. `MxAccessGalaxyBackend.SubscribeAsync` wires `OnTagValueChanged` that fans values out per-tag to every subscription listening (one MXAccess subscription, multi-fan-out via `_refToSubs` reverse map). `UnsubscribeAsync` only calls `mx.UnsubscribeAsync` when the last sub for a tag drops. |
| Medium 4 | `WriteValuesAsync` doesn't await `OnWriteComplete` | `MxAccessClient.WriteAsync` rewritten to return `Task<bool>` via the v1-style TCS-keyed-by-item-handle pattern in `_pendingWrites`. TCS added before the `Write` call, awaited with configurable timeout (default 5s), removed in finally. Returns true only when `OnWriteComplete` reported success. `MxAccessGalaxyBackend.WriteValuesAsync` reports per-tag `Bad_InternalError` ("MXAccess runtime reported write failure") when the bool returns false. |
## Cross-cutting deferrals — resolved
| Deferral | Resolution |
|----------|------------|
| Deletion of v1 archive | Phase 3 PR 18 deleted the source trees; PR 61 closed `V1_ARCHIVE_STATUS.md` |
| Wonderware Historian SDK plugin port | `Driver.Galaxy.Host/Backend/Historian/` ports the 10 source files (`HistorianDataSource`, `HistorianClusterEndpointPicker`, `HistorianHealthSnapshot`, etc.). `MxAccessGalaxyBackend` implements `HistoryReadAsync` / `HistoryReadProcessedAsync` / `HistoryReadAtTimeAsync` / `HistoryReadEventsAsync`. `GalaxyProxyDriver.MapAggregateToColumn` translates `HistoryAggregateType` → `AnalogSummaryQuery` column names on the proxy side so Host stays OPC-UA-free. |
| MxAccess subscription push frames | Closed under Medium 3 above |
| Wonderware Historian-backed HistoryRead | Closed under the Historian port row |
| Alarm subsystem wire-up | PR 14. `GalaxyAlarmTracker` in `Backend/Alarms/` advises the four Galaxy alarm-state attributes per `IsAlarm=true` attribute (`.InAlarm`, `.Priority`, `.DescAttrName`, `.Acked`), runs the OPC UA Part 9 lifecycle simplified for the Galaxy AlarmExtension model, raises `AlarmTransition` events (Active / Acknowledged / Inactive) forwarded through the existing `OnAlarmEvent` IPC frame. `AcknowledgeAlarmAsync` writes operator comment to `<tag>.AckMsg` through the PR 4 TCS-by-handle write path. |
| Reconnect-without-recycle in MxAccessClient | Closed under High 2 (reconnect-with-replay loop is the "without-recycle" path — supervisor recycle remains the fallback). |
| Real downstream-consumer cutover | Out of scope for this repo; phased Year-3 rollout per `docs/v2/plan.md` §Rollout — not a Phase 2 deliverable. |
## 2026-04-20 test baseline
Full-solution `dotnet test ZB.MOM.WW.OtOpcUa.slnx` on `v2` tip:
@@ -736,7 +736,7 @@ Each step leaves the system runnable. The generic extraction is effectively free
6.**Wire `Server`** — bootstrap from Configuration using an instance-bound credential (cert/gMSA/SQL login), fail fast if the credential is rejected, register drivers, start Core.
7.**Scaffold `Admin`** — Blazor Server app with: instance + credential management, draft/publish/rollback generation workflow (diff viewer, "publish to fleet", per-instance override), and core CRUD for drivers/devices/tags. Driver-specific config screens deferred to later phases.
**Phase 2 — Galaxy driver (prove the refactor)**
**Phase 2 — Galaxy driver (prove the refactor) — ✅ CLOSED 2026-04-20** (see [`implementation/exit-gate-phase-2-closed.md`](implementation/exit-gate-phase-2-closed.md))
8.**Build `Galaxy.Shared`** — .NET Standard 2.0 IPC message contracts
9.**Build `Galaxy.Host`** — .NET 4.8 x86 process hosting MxAccessBridge, GalaxyRepository, alarms, HDA with IPC server
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.
