Joseph Doherty
7b5a5a6f34
Normative first: Component-StoreAndForward.md:83 specified the whole chunked, ack-confirmed SfBufferSnapshotChunk resync protocol, which Phase 2 deleted. It is rewritten rather than removed — the failure modes it reasoned about still exist, they are just bounded differently — and it now states the duplicate-delivery bound explicitly: a message can be delivered twice only when the OLD primary delivered it and the status change had not yet replicated when the gate flipped. One flush interval plus the in-flight ack, and unlike the old model it does NOT grow with backlog depth or with how long a node was absent. The N1 directional-authority and N5 orphan-row hazards are recorded as structurally gone, not merely unguarded. Frame-size known-issue amended: its 2026-06-26 resolution replaced the intra-site hop with notify-and-fetch; Phase 2 then deleted notify-and-fetch itself, so the 128 KB Akka frame constraint no longer applies to that hop in any form. Successor ceiling recorded (4 MB gRPC cap via MaxBatchSize, which batches by ROW COUNT), including that the failure mode differs — an oversized gRPC message is rejected, not silently dropped. Deployment docs gain the two operational constraints that have no home in code: a site pair must be stopped and started TOGETHER (the SfBufferSnapshot compat handler that made a mixed-version pair converge went with the replicator, and a mixed pair now diverges silently), and a node offline beyond TombstoneRetention can resurrect deleted rows on rejoin. Both CLAUDE.md files corrected — each still said Phase 2 was NOT started. Definition of done closed: build 0 warnings, all 10 suites green (3509 tests, 0 failures, 0 skips). Two DoD items needed amending rather than ticking: the stale-symbol grep still matches 4 lines, all deliberate comment prose recording what was deleted (a literal zero would delete the explanations that stop the old design coming back), and the live gate has 10 evidence items, not the 9 the checklist claimed. Deletes the phase2 resume-state scratch doc, which said to delete it on landing. Claude-Session: https://claude.ai/code/session_01BL2Vu1ESDQ9SCN4gVKkdts
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.