dohertj2/mxaccessgw
1
0
Fork 0
Code Issues 3 Pull Requests 1 Actions Packages Projects Releases Wiki Activity

docs: alarm acknowledgement writes AckMsg as the authenticated operator

Browse Source 
Claude-Session: https://claude.ai/code/session_016J6isfcgqy4SB2RK3ZvFvT
This commit is contained in:
Joseph Doherty
2026-10-19 19:44:18 -04:00
parent 2858e42e80
commit 9409488008
12 changed files with 243 additions and 105 deletions
Download Patch File Download Diff File Expand all files Collapse all files
docs/GatewayConfiguration.md
+9 -8
View File
@@ -442,17 +442,18 @@ behavior.
| `MxGateway:Alarms:ReconcileIntervalSeconds` | `30` | How often the monitor re-resolves and, on material change, hot-swaps the subtag fallback watch-list, then reconciles its in-process alarm cache against the worker's authoritative active-alarm snapshot. The acknowledged watch-list fingerprint advances only after an OK worker reply. Floored at 5 seconds. |
| `MxGateway:Alarms:PollIntervalMilliseconds` | `500` | Cadence at which the worker's STA polls the AVEVA alarm consumer (`GetXmlCurrentAlarms2`) for the active-alarm snapshot the live feed diffs. Must be between `100` and `3600000` (one hour): every poll is a COM call plus an XML parse on the same STA that serves reads and writes, so a tighter cadence starves the command path, while a value above an hour stops being a cadence and silently disables alarm polling. The gateway conveys the value to the worker via the `MXGATEWAY_ALARM_POLL_INTERVAL_MS` environment variable; a missing or out-of-range value leaves the worker on the 500 ms default rather than failing the session. |
| `MxGateway:Alarms:MaxAlarmsPerFetch` | `1024` | Cap the worker passes to `GetXmlCurrentAlarms2`'s `maxAlmCnt`. Must be between `64` and `65536` — the worker is a 32-bit process that materializes each reply as one BSTR plus a full `XmlDocument`, so an unbounded cap faults the STA with an out-of-memory rather than merely slowing it. It doubles as the **truncation threshold**: a fetch returning exactly this many records is treated as truncated, because the COM API caps its reply with no "more available" flag. On a truncated poll the worker retains the alarms the capped reply could not mention instead of letting their absence read as a clear, and logs a rate-limited `AlarmSnapshotTruncated` warning to its stderr (identifiers and counts only). **Remediation when you see that warning: raise this value** so the steady-state active-alarm count fits inside one fetch. A galaxy permanently above the cap holds stale entries in the snapshot until a sub-cap poll, and loses clear→re-raise cycles that happen entirely out of window (see `docs/DesignDecisions.md`). Conveyed to the worker via the `MXGATEWAY_ALARM_MAX_ALARMS_PER_FETCH` environment variable; a missing or out-of-range value leaves the worker on the 1024 default. |
| `MxGateway:Alarms:AckClientName` | `MxGateway` | MXAccess client name the alarm worker's ack writer registers with; the Historian records it as each acknowledgement's OperatorNode. 1-64 printable characters. Conveyed via `MXGATEWAY_ALARM_ACK_CLIENT_NAME`. |
The alarm monitor is independent of client sessions: `AcknowledgeAlarm` and
`StreamAlarms` are session-less RPCs served by the monitor.
The worker also reads `MXGATEWAY_USE_MANAGED_ALARM_ACK` (inherited from the
gateway process). Setting it to `1` is meant to route GUID-keyed acknowledges
through AVEVA's managed alarm client, but a live test (2026-10-18) showed the
path cannot work as built: the managed client fails to register alongside the
worker's wnwrap reader and the worker silently falls back to wnwrap. Leave it
unset. It has no `MxGateway:*` option. See
[AlarmClientDiscovery](./AlarmClientDiscovery.md) ("Opt-in managed GUID ack").
`AckClientName` is the MXAccess client name the alarm worker's ack writer
registers its dedicated `LMXProxyServer` with. The Historian records it as the
OperatorNode of each acknowledgement, so it identifies the gateway as the
acknowledging node. The gateway passes it to each worker through the
`MXGATEWAY_ALARM_ACK_CLIENT_NAME` environment variable. Startup validation
rejects an empty value, a value over 64 characters, or one containing control
characters.
### Alarm fallback options
@@ -471,7 +472,7 @@ native wnwrap alarm-manager provider and the subtag-monitoring fallback.
| `MxGateway:Alarms:Fallback:Discovery:ExcludeAttributes` | _(empty)_ | Attribute paths to remove from the merged watch-list (case-insensitive). The exclude is applied after the Repository-derived rows and the explicit `IncludeAttributes` entries are combined, so an exclude that matches an explicit include suppresses it too — excludes win. Ignored when `UseGalaxyRepository` is `false`. |
| `MxGateway:Alarms:Fallback:Subtags:Active` | `InAlarm` | Subtag name for the in-alarm boolean. Confirmed AVEVA `AlarmExtension` field name. |
| `MxGateway:Alarms:Fallback:Subtags:Acked` | `Acked` | Subtag name for the acknowledged boolean. Confirmed AVEVA `AlarmExtension` field name. |
| `MxGateway:Alarms:Fallback:Subtags:AckComment` | `AckMsg` | Subtag name for the acknowledgement comment write target. Writing this subtag performs the acknowledge in AVEVA. Confirmed AVEVA `AlarmExtension` field name. When empty, the ack-comment write path is disabled. |
| `MxGateway:Alarms:Fallback:Subtags:AckComment` | `AckMsg` | Subtag name for the acknowledgement comment write target. Writing this subtag, as the authenticated operator, performs the acknowledge in AVEVA. Confirmed AVEVA `AlarmExtension` field name. When empty, the alarm is not ackable and the RPC returns `InvalidRequest`. |
| `MxGateway:Alarms:Fallback:Subtags:Priority` | `Priority` | Subtag name for the alarm priority / severity value. Confirmed AVEVA `AlarmExtension` field name. |
Validation rules: