CentralFailoverControl lives in Components/Health/ (matching AuditKpiTiles /
SiteCallKpiTiles) rather than inline in Health.razor, so it is testable without
standing up the whole dashboard's DI graph.
- Admin-gated via AuthorizeView + RequireAdmin. The Health page itself is
intentionally all-roles, so the gate belongs on the control, not the page.
- Disabled with an explanatory title when the pair has no online standby;
the authoritative guard remains server-side against live cluster membership.
- Confirmation dialog (IDialogService, the page idiom) warns that singletons
hand over, in-flight work on the active node is interrupted, and THIS PAGE
will disconnect and reconnect against the new active node -- Traefik routes
the UI to the node being restarted, so a working failover otherwise reads as
a crash the admin caused.
- A refused failover (service returns null) surfaces the refusal; the UI never
reports a failover that did not happen.
7 bUnit tests. Two harness requirements that bit first: AuthorizeView needs a
cascading AuthenticationState (the app supplies it from the layout), and
BunitContext pre-registers a placeholder IAuthorizationService that throws on
policy evaluation -- both handled the same way NavMenuTests documents.
Runbook paragraphs added to Component-ClusterInfrastructure.md (new Manual
Failover section) and docker/README.md.
Wire the operator Alarm Summary page to the transient per-site live alarm
cache (ISiteAlarmLiveCache, T4). Live-cache-first: on site select the page
subscribes and rebuilds rows/rollup from near-real-time onChanged deltas; the
15s poll is kept untouched as the authority for NotReporting and as the
safety net whenever the cache is not live (pre-seed or degraded stream). Both
paths mutate shared state only via the Blazor dispatcher, so they never race,
and each rebuild is an idempotent snapshot.
- IAlarmSummaryService.BuildFromLiveAlarms: flattens a live AlarmStateChanged
snapshot to AlarmSummaryRows with the same deterministic instance-then-name
sort as GetSiteAlarmsAsync; NotReporting always empty on the live path.
- AlarmSummary.razor: inject ISiteAlarmLiveCache; subscribe on select,
re-subscribe on site change, unsubscribe on leave + Dispose.
- Tests: service BuildFromLiveAlarms flatten/sort/empty; page subscribe,
poll-fallback render, onChanged rebuild, unsubscribe on leave/change/dispose.
Claude-Session: https://claude.ai/code/session_01MtdgwpEeCUn6cUA5f1LMPj
Joseph Doherty