WP2.6 (arch-review remediation, cross-cutting misc):
- SiteExternalSystemRepository: name/ID-indexed ExternalSystemDefinitionCache replaces
the fetch-all + reverse-map scan on every by-ID/method lookup; loaded once per
redeploy, invalidated by DeploymentManagerActor after HandleDeployArtifacts applies
external-system changes. Static JsonSerializerOptions for method-list parsing.
- Inbound API: short-TTL ApiMethodCache fronts the per-request ApiMethod repository
fetch; invalidated by name via the existing ScriptArtifactChangeSubscriber/
IScriptArtifactChangeBus pipeline, self-healing via TTL for changes the bus
doesn't cover (e.g. Management API edits).
- StoreAndForward: the cached-call audit-observer queue — the one unbounded channel
left in the system — is now bounded (ObserverQueueCapacity, default 10,000) with
DropOldest overflow and a dropped-notification counter.
- SiteStreamManager: alarm state changes now travel a dedicated publish
source/broadcast hub, isolated from the (far higher-volume) attribute path, so an
attribute storm can no longer evict a pending alarm transition; the alarm hand-off
queue is bounded with a drop counter surfaced on the site health report
(SiteStreamAlarmDropCount via the new SiteStreamAlarmDropReporter), and publishing
is skipped entirely at zero subscribers on either path.
- CLI ManagementHttpClient: explicit 30s HttpClient.Timeout on the shared
construction (was the 100s framework default), overridable via
SCADABRIDGE_HTTP_TIMEOUT_SECONDS.
Deviation: the failback-probe heartbeat item is NOT included — its only viable
surface (CentralChannelProvider.cs / heartbeat consumers) lives entirely in the
Communication project, explicitly off-limits to this work package this phase.
Tests: SiteRuntime.Tests (550), InboundAPI.Tests (278), StoreAndForward.Tests (133),
CLI.Tests (390), HealthMonitoring.Tests (97) — all green after full solution build.
Joseph Doherty