Joseph Doherty
677263af57
The per-IP unlock throttle's counters were a process-local ConcurrentDictionary on each central node, so the effective fleet cap was N x MaxUnlockAttemptsPerIpPerHour per client (failing over to the other node handed the client a fresh budget) and a node restart cleared the window outright. The window now lives in the central MS SQL BundleUnlockAttempt table — the HA store both central nodes already share, so no new infrastructure, no new port, no consensus protocol: - Commons: BundleUnlockAttempt entity + IBundleUnlockAttemptRepository. - ConfigurationDatabase: entity config (one index, IX_BundleUnlockAttempt_Client_Attempted, serving both the windowed count and the prune), repository (AsNoTracking count, ExecuteDeleteAsync prune), DbSet, DI registration, migration AddBundleUnlockAttemptTable + the hand-written idempotent production script under docs/plans/sql/. - Transport: IBundleUnlockAttemptWindow seam + SqlBundleUnlockAttemptWindow (singleton; resolves the scoped repository from its own scope per call, like the central purge singletons). BundleUnlockRateLimiter keeps the policy and gains TryRegisterAttemptAsync; BundleImporter.LoadAsync calls it. Behaviour preserved from row 44: locked bundles spend no hourly budget (the lockout check still runs first), throttle denials burn no per-bundle strike and are NOT recorded so they cannot roll the window forward, unattributable clients share the stricter <unattributed> bucket, and the budget counts attempts rather than failures. Config keys and their semantics are unchanged, so the rig's 500 override stays valid. Three deliberate trades, documented in both Transport docs: - FAILS OPEN. A store error logs a Warning naming the client and cap, and permits the attempt. This is a best-effort rate cap over an already authenticated, Administrator-gated surface — the availability of legitimate imports outranks the cap, and a DB blip must not make the import wizard unusable. Falling back to the process-local window was considered and rejected: it would still block a legitimate operator's 11th import. - Approximate. Count-then-insert is not atomic across nodes, so simultaneous attempts can overshoot by the number in flight — bounded, self-correcting within the window, and not worth provider-specific raw SQL. - Pruned opportunistically on the unlock path (CAS-claimed at most every 15 min per process, bounded to 1000 rows, retaining 2x the window, best-effort try/catch) rather than by a new background service — Transport owns no central scheduler. Same shape as DeploymentService's terminal-record sweep. Tests: Transport.IntegrationTests 116 passed (+10 — two limiter instances over one store enforcing a single combined window, restart durability, denials burning no budget, sliding release, bucket isolation, store-failure fail-open, caller-cancellation not swallowed, no-shared-window fallback, prune and its negative control); ConfigurationDatabase 395 passed (+5).
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.