Joseph Doherty
f02e116688
ReadStoreSnapshotAsync's snapshot is read off the actor thread and consumed only when its piped message lands. Row 101 guarded the DEFINITIONS half of that race; the CONFIG half was left to machinery whose reach is time-limited, and both legs of the instance reconcile sweep were reachable through it: - Row-72 leg: a read dispatched before a deploy's persist, landing after the deploy completed AND after the pipeline released ownership, carries the revision the deploy replaced. TryRestartStaleInstance then "repairs" the instance BACKWARD, re-deploying the snapshot's own superseded ConfigJson. InstanceIsOwnedByADeployPipeline covers only in-flight deploys, and the per-revision claim has never seen the old revision, so nothing stopped it. - Row-78 leg: a read dispatched before a delete/disable commits still shows an enabled row while the actor is already stopped, so StartStoredInstance resurrects it — and delete clears _sweepAttemptedRevisions, freeing the claim. Both verified real by neutralising the freshness check and re-running the new tests (the fail-before site event literally reads "running revision rev-2 is stale, applying stored revision rev-1"; the deleted instance came back). _definitionsWriteGeneration becomes _storeWriteGeneration, covering both tables (the snapshot is one consistent read and is discarded whole, so one counter is the right shape); DefinitionsGenerationAtRead -> StoreGenerationAtRead on both internal records. The generation is now bumped at BOTH ends of every mutation — when the off-thread write is dispatched and when its completion message lands — because the config paths advance actor state before the write, so an initiation-only bump would let an in-window read look fresh. Disable, delete and the init-failure rollback have no actor-thread completion message of their own, so a minimal StoreWriteCompleted self-message carries the bump for them. CDC-replicated writes, snapshot resyncs, restored files and SiteReconciliationActor's fetch deliberately do NOT bump: discovering exactly those is the sweep's reason to exist. A stale sweep result is now dropped WHOLE (no overlay apply, no start, no restart). A stale boot load cannot be dropped — startup must finish — so it re-dispatches LoadDeployedConfigs(); a fifth consecutive superseded read is applied anyway with a Warning, and a late one arriving after the boot completed is dropped rather than looping against the S5 retry timer. Tests: three fail-before regressions (backward restart, resurrection, boot re-read) plus two guard twins pinning that the legitimate row-72 restart and row-78 start still fire on a current-generation snapshot. The row-101 definitions tests keep passing; FreshEmptySweepSnapshot's hardcoded generation moves 1 -> 2 now that one artifact apply bumps at both ends. Docs: Component-SiteRuntime.md's stale-snapshot paragraph now describes the whole snapshot (both halves, both consumers, the boot re-dispatch, the CDC-no-bump rule), the components mirror follows, and the arbitration memo gains §11 extending §10 to the config half.
Component Reference Documentation
Developer-reference docs for each ScadaBridge component, describing how the shipped
code in src/ actually works — with real code examples. These complement the
design specs in docs/requirements/: the specs say what a
component should do and why; these docs say how the code does it.
Reference docs exist for 24 of the 27 components (plus the shared TreeView, listed below). ScriptAnalysis (#25), KpiHistory (#26), and DelmiaNotifier (#27) are pending — tracked in ../plans/2026-07-08-deferred-work-register.md.
| # | Component | Description |
|---|---|---|
| 1 | Template Engine | Template modeling, inheritance, composition, flattening, diffs, and semantic validation as implemented by the engine's services. |
| 2 | Deployment Manager | The central deployment pipeline: deployment identity and idempotency, per-instance operation locks, state transitions, all-or-nothing site apply, and artifact deployment. |
| 3 | Site Runtime | The site actor hierarchy (Deployment Manager singleton, Instance, Script, and Alarm actors), script compilation and execution, the site-wide stream, native alarms, and supervision. |
| 4 | Data Connection Layer | Protocol adapters (OPC UA, MxGateway), the Become/Stash connection state machine, reconnect and re-subscribe, and the native-alarm subscription seam. |
| 5 | Central–Site Communication | ClusterClient command and control plus gRPC server-streaming, the central and site communication actors, receptionist registration, and per-site contact points. |
| 6 | Store-and-Forward Engine | Site-only buffering, fixed-interval retry, parking, SQLite persistence, standby replication, and the operation-tracking store. |
| 7 | External System Gateway | Script-facing HTTP/REST and database access, the Call and CachedCall modes, and transient versus permanent error classification. |
| 8 | Notification Service | Central notification-list and SMTP definitions, the per-type delivery adapters, and OAuth2 or Basic SMTP delivery. |
| 9 | Central UI | The Blazor Server app structure, authentication, real-time updates (SignalR and gRPC), and the management pages. |
| 10 | Security & Auth | LDAP bind authentication, cookie and JWT sessions, role-based and site-scoped authorization, and shared Data Protection keys. |
| 11 | Health Monitoring | Site metric collection and central aggregation, report and heartbeat intervals, offline detection, and dead-letter monitoring. |
| 12 | Site Event Logging | The site-local SQLite event log, retention and storage cap, daily purge, and paginated central query access. |
| 13 | Cluster Infrastructure | The ClusterOptions model and validation for active/standby clustering, split-brain resolution, and failover. |
| 14 | Inbound API | POST /api/{method} script invocation, API-key authentication, the extended type system, and inbound-request auditing. |
| 15 | Host | The deployable binary: role-based component registration, Akka bootstrap, ASP.NET Core hosting, and the readiness and active-node health endpoints. |
| 16 | Commons | Shared POCO entities, repository and service interfaces, message contracts, and the Types/Interfaces/Entities/Messages namespace layout. |
| 17 | Configuration Database | The EF Core DbContext, repository implementations, the audit service, secret encryption, and migration and partition maintenance. |
| 18 | Management Service | The ManagementActor admin command surface, its HTTP endpoints, and ClusterClientReceptionist registration. |
| 19 | CLI | The System.CommandLine tool over the HTTP Management API — its command groups, config file, and output formats. |
| 20 | Traefik Proxy | The reverse proxy fronting the central cluster, active-node routing via /health/active, and the Docker topology configuration. |
| 21 | Notification Outbox | The central NotificationOutboxActor, the Notifications table, the dispatcher loop, retry and parking, and KPIs. |
| 22 | Site Call Audit | The central SiteCallAuditActor, the SiteCalls mirror table, telemetry ingest, and the parked-call Retry/Discard relay. |
| 23 | Audit Log | The append-only audit store: site SQLite hot-path, gRPC telemetry, central ingest and reconciliation, redaction, retention, and KPIs. |
| 24 | Transport | Encrypted bundle export and import, dependency resolution, conflict detection, and BundleImportId-correlated audit. |
| 25 | Tree View | The reusable Blazor tree component — parameters, selection modes, and usage in the Central UI. |
Related Documentation
- Component design specs — the spec each component implements.
- Documentation Style Guide — the writing conventions these docs follow.
- README — the repository master index.