Merge #605: Galaxy gateway seam hardening (advise-failure unmark, derived historian health, duplicate attributeRef surfaced, bounded subscribe-once read)

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
2026-10-08 06:52:49 -04:00
parent 0544287f26 7c4c7f9653
commit ba3d882897
8 changed files with 132 additions and 90 deletions
@@ -113,3 +113,6 @@ The session-less alarm feed (`GatewayGalaxyAlarmFeed`) and alarm acknowledger (`
 - **Replay gaps** (`galaxy.events.replay_gaps`): the gateway signals that events were evicted from its replay ring before we could read them. The driver responds by re-issuing `SubscribeBulk` for every tracked subscription — MXAccess delivers an initial value per item on subscribe, so re-subscribing *is* the re-snapshot the contract asks for. It does **not** restart the event pump (the stream carrying the sentinel is healthy) and it honours `Reconnect:ReplayOnSessionLost=false` by logging and standing down, on the grounds that an operator who delegated recovery to the gateway did not ask for a re-subscribe on a different trigger.
  ⚠️ This cannot currently fire: the sentinel is only emitted on a stream opened with `after_worker_sequence > 0`, and the driver opens with `0`, which the gateway treats as "fresh stream, not a resume". Enabling resume is a bigger change than it looks — the sequence is only meaningful **within one gateway session**, and the reconnect path recreates the session, so a remembered sequence replayed against a fresh session would set the server's live watermark *above* every event it is about to send, silencing the stream rather than recovering it.
 - **Undecodable values** (`galaxy.events.undecodable`): a value kind this driver has no CLR representation for is published as **`BadTypeMismatch` with a null value**, and the first occurrence of each distinct kind is logged. It is *not* published as a null carrying the event's own quality: an MXAccess event can be Good-quality while the payload is one we cannot map, and a good null is indistinguishable from a genuine null reading — a client would consume a value it never received as a real one, with the failure visible only in a log. Non-zero here means the gateway is sending a wire type `MxValueDecoder` has no mapping for and those readings are being lost; the fix is a decoder mapping, not a quality change.
+- **Duplicate `attributeRef` (#605 / 06-S-13)**: two authored RawPaths dialling the same Galaxy attribute are both dialled, but the reverse map is first-wins, so value fan-out and alarm `ConditionId` surface under the first RawPath only. The loser is logged at Warning and recorded in the skipped-tag ledger with the winner path in the reason.
+- **Subscribe-once reads are bounded (#605 / 06-S-3)**: `ReadAsync` on the production path (SubscribeBulk, first event, Unsubscribe) carries an internal 30 s deadline in addition to the caller token; slots that never publish come back `BadTimeout`, so `CancellationToken.None` can no longer hang on a silent tag.
+- **Supervisory advise is retried after a thrown failure (#605 / 06-S-12)**: the writer marks an item handle advised before the call; a thrown advise (not just a non-OK status) now unmarks it, fails the write closed and re-advises on the next write.