A notifier folder read one event source, its NodeId identifier (a RawPath or an EquipmentId). AVEVA stores a
Galaxy object's A&E history under the object's tag_name (Source_Object), so AVEVA's own alarm and event
history reached no production folder. Its lower-case property keys were also missed, so every row read
Severity 1 with no ConditionName.
Sources. A folder's event history now reads its own source plus the Galaxy object of every native condition
that fires on it live: those parented under it and those WireAlarmNotifiers wired to it. Live and history use
the same membership. The object comes from the condition's Galaxy alarm reference, its raw tag's attributeRef,
up to the first '.':
- The composer reads it with the driver's own parser (GalaxyAttributeRef, shared with GalaxyDriver), only for
a GalaxyMxGateway tag with an alarm (RawTagPlan.NativeAlarmReference, part of plan equality).
- The applier binds it after materialising the condition (IOpcUaAddressSpaceSink.BindNativeAlarmHistory,
forwarded by the deferred sink). A rebuild or the condition's removal forgets it.
Each object is read with the #882 rule: its own events and <Object>.<Attribute> rows, never a prefix sibling.
Fan-out. historiangw's ReadEvents filter is a single predicate, so there is one request per source; the wire
contract is unchanged. EventSourceFanOut merges the reads as one source:
- order is (time, source position, arrival), reversed for a reverse read; ties are never re-sorted by EventId,
so the boundary skip stays stable;
- duplicates by EventId are dropped and the merge is cut to the cap;
- a truncated source bounds the page at the time it stopped.
Paging, continuation points (bound to the whole source set), the walked-back reverse read and the tie-cluster
over-fetch are unchanged. A folder with one source is read exactly as before.
ACL. Every source is read inside the folder's own HistoryRead, after AuthorizeHistoryRead (#826). A denied
folder reads nothing and fails closed.
Mapping (EventMapper, property names now case-insensitive):
- Severity: an AVEVA row's priority goes through GalaxyAlarmPriority, the table live Galaxy alarms use
(MxAccessSeverityMapper now delegates to it), so history matches live. Otherwise severity (OtOpcUa's own
rows, which AVEVA stores lower-cased), clamped. AVEVA's own 1-4 severity is ignored. The table ranks a
higher priority as more severe, which inverts AVEVA's convention: filed as #887.
- An AVEVA row whose source_conditionvariable names a native condition that fires on the folder takes that
condition's SourceNode and live ConditionName. Otherwise ConditionName is alarmname or the condition
variable's attribute.
- alarm_id/alarmid map to AlarmId.
Tests:
- GalaxyEquipmentEventHistoryWireTests (4, real SDK session, production Gateway backend, AVEVA-shaped fake
gateway): equipment EqA backed by objects Oven_007 + OvenDoor_07. Covers object and attribute events from
both objects, the prefix sibling excluded, cross-object and in-object ties, forward paging at 1-4 a page,
reverse whole and paged, SourceNode/ConditionName/Severity, the raw device folder, ACL deny with no backend
call plus a granted positive control, and a rebuild forgetting the bindings.
- EventSourceFanOutTests (8), EventMapper AVEVA cases (11), GalaxyAttributeRefTests (16), a composer test and
an applier ordering test.
- Mutation-checked, 17 mutants, all killed. Covered: parent-only membership, no scope, a case-sensitive
condition match, no condition rewrite, no truncation bound, EventId tie order, no sort, no cap, no stop at
the bound, unreversed source order, no dedupe, no '.' boundary, priority ignored, case-sensitive keys, no
applier bind, no deferred forward, and a composer that ignores the driver type. The forget-on-rematerialise
guard survives as belt-and-braces: the rebuild clear covers it.
- Live, read-only, no WinRM, vd03 HistorianGateway ea9f21c: equipment folder EQ-886-ZipsenLeft (objects
DevWinPlatform + Left_001). It read 0 events before and 92 now, equal to the unfiltered read's rows for both
objects. 1/7-event pages and reverse whole/5-event pages agree, and 73 rows resolve to their live condition.
diff_runs vs the #882 run: 221/226 identical. The 5 that differ are expected: DevWinPlatform Severity
1 -> 750/1000, and #881 capabilities.
Claude-Session: https://claude.ai/code/session_01GT67ACmpMR7b9LGRPLijMi
HistorianGateway answers a per-source ReadEvents (Source_Object = DevWinPlatform) with the
object's own events (SourceName DevWinPlatform) AND its attribute alarms, which it reports as
<Object>.<Attribute> (Source_ProcessVariable, e.g. DevWinPlatform.CPULoadAvg). The Gateway
backend's defensive client-side source filter compared SourceName for equality, so it dropped
the attribute alarms: 70 of the 72 DevWinPlatform events on vd03.
The filter (and the past-the-cap "more events" signal) now uses EventSourceMatch: the source
itself, or <source>.<anything> on the '.' boundary, ordinal. DevWinPlatform never matches
DevWinPlatform2 or DevWinPlatform2.X. This needs no wire change and still makes one request.
Each event keeps its own SourceName. SourceNode stays the condition its stored alarm id names,
which is null for AVEVA rows. The attribute events ride the notifier's own read, so the
per-folder HistoryRead verdict (#826) governs them: a denied folder answers
BadUserAccessDenied before any backend call. The SqlServer and QuestDB backends still match
exactly; they hold only OtOpcUa's own events.
Tests:
- GatewayAttributeEventSourceTests (16): the boundary theory, attribute-in/sibling-out through
the data source, the drain signal, and an exact attribute-named read.
- AttributeEventHistoryWireTests (2, over a real SDK session with the production Gateway
backend on an AVEVA-shaped deterministic gateway): object + attribute events with their own
SourceName, a prefix sibling excluded, paging, and the ACL-on deny with no backend call plus a
granted positive control.
- Mutation-checked: exact match fails both wire tests; dropping the '.' boundary fails the
wire sibling check and 6 unit tests.
- Live AVEVA harness re-run against vd03 HistorianGateway ea9f21c (read-only, no WinRM):
folder DevWinPlatform 2 -> 72 events (whole, 72 1-event pages, reverse); the new #882 check
passes; 221 of 225 shared cases are identical to the #801 SDK2 baseline, and the 4 that
differ are exactly the DevWinPlatform event cases. Recorded in aveva-history-801.md.
Follow-up #886: production folders name RawPaths/EquipmentIds, not Galaxy objects, plus the AVEVA
severity/condition property mapping.
Claude-Session: https://claude.ai/code/session_01GT67ACmpMR7b9LGRPLijMi
Both builds served HistoryRead from the real AVEVA Historian via the DEV
HistorianGateway (vd03, ea9f21c): 225 cases / 3,855 rows / events, 0 differences.
Raw also matches direct SQL on Runtime.dbo.History (6/6) and histgw-cli; simple
aggregates match a recomputation from raw (336/336). Modified, HistoryUpdate,
seven refused aggregates and HistoryServerCapabilities answer as before. No write
reached the historian. Findings (pre-existing, not SDK): all HistoryServerCapabilities
booleans false; AVEVA attribute-alarm events unreachable per source.
Claude-Session: https://claude.ai/code/session_01GT67ACmpMR7b9LGRPLijMi
Joseph Doherty