Joseph Doherty
7a7d345b89
Six sleeps across four test files stood in for an observable edge. Each preceded an
ABSENCE assertion (or "settled" before one), so they failed toward false-pass rather than
flake: the assertion could not distinguish "the mechanism ran and correctly stayed quiet"
from "the mechanism had not run yet".
ScriptDeadlineAtEnqueueTests (two sleeps, the worst offender)
- :105 Thread.Sleep(2s) — now two explicit edges: the run must be observably QUEUED
(scheduler.QueueDepth >= 1, never checked before), then the wait polls until the 1 s
budget has elapsed, bailing early if the run leaves the queue, and asserts it is STILL
queued afterwards. The test now proves the design claim it was named for — queue wait
burns the run's budget — instead of assuming it.
- :128 Thread.Sleep(2s) + Assert.Equal(0, DetachedThreadCount) — replaced by a positive
control: a second script that genuinely wedges a worker, on the same scheduler, same
1 s timeout + 1 s grace, armed strictly later. Its stuck report is the edge; once it
lands, every watchdog armed at or before it has provably finished its grace delay. The
absence is then asserted per script name, and the detach counter is pinned at 1 (the
wedged run) rather than 0 — which a counter that never moves also satisfied.
DeploymentWarmThenGateTests (:117 plus two sibling Task.Delay(500) startup waits)
- The manager calls SetInstanceCounts unconditionally when its startup config load
completes, so a report counter on the test collector is the startup edge. The
empty-site zero is now the manager's own observation instead of an untouched field.
SiteAlarmLiveCacheServiceTests (:195, :216)
- Both sampled IsLive once after a fixed sleep. Now they poll continuously across three
linger windows on a new teardown observable (the mock client counts subscription
cancellations), so a stop at any instant inside the window is caught, and each closes
with a positive control proving that counter moves.
DataConnectionActorTests (:435)
- A Task.Delay(200) "settle" after an AwaitCondition on a connect counter. The counter
only proves ConnectAsync was CALLED; the actor is still Connecting until it processes
the piped result. Now waits for the Connected health publication that BecomeConnected
emits, so the subscribe under test provably runs against Connected rather than being
silently stashed. (The stash path keeps its own coverage in
WP6_ConnectingState_StashesSubscribeRequests.)
Negative controls (product broken in the working tree, old vs new test compared):
- Stuck-script watchdog disabled entirely: OLD test passed 2/2, NEW test failed. The
whole watchdog could be deleted and the old assertions were satisfied.
- Startup reporting a phantom instance count and taking longer than 500 ms: OLD passed
2/2, NEW failed (expected 0, actual 1).
- Linger cancellation disabled + the remaining-viewer guard dropped, so the stream is
torn down under a live viewer while IsLive keeps reporting true:
Resubscribe_Within_Linger OLD passed 2/2, NEW failed. (Last_Viewer_Leaving caught this
particular break in the old form too, via a later assertion — its strengthening is the
teardown observable and the positive control, not a false-pass fix.)
- DataConnectionActorTests :435 has no false-pass demo: the sleep guarded no assertion
there, and the change is determinism plus proving the claimed state.
Also fixes a latent race these timing changes exposed in
InstanceActorChildAttributeRaceTests: it resolved child actors single-shot immediately
after construction, but ResolveOne throws until the child's cell is published on the
parent AND the cell's Actor property stays null until the child's constructor has run on
its own mailbox thread. Neither is ordered against the test thread, so it failed both ways
under full-suite load (~1 run in 6 once the sleeps above stopped padding the schedule;
14/14 green on the unmodified tree, so it was latent, not new). Resolution now retries to
a bounded deadline; the assertion is unchanged.
Verification: SiteRuntime.Tests 8/8 green (605 tests), Communication.Tests 3/3 (717),
DataConnectionLayer.Tests 3/3 (319). Test-only change — no src/ modifications.
ScadaBridge
ScadaBridge is a centrally-managed, distributed SCADA configuration and deployment platform built on Akka.NET, running across a central cluster and multiple site clusters in a hub-and-spoke topology.
Overview
This repository is the full implementation project for ScadaBridge — the C#/.NET source (src/), tests (tests/), deployable Docker topology (docker/, docker-env2/, infra/), and the design documentation (docs/) that the code implements. This README is the master index: it links the per-component design specs (the spec the code in src/ implements), the per-component reference docs (how the shipped code works), and shows the system architecture. The solution file is ZB.MOM.WW.ScadaBridge.slnx.
Technology Stack
| Layer | Technology |
|---|---|
| Runtime | .NET, Akka.NET (actors, clustering, remoting, persistence, streams) |
| Central UI | Blazor Server (ASP.NET Core + SignalR) |
| Inbound API | ASP.NET Core Web API (REST/JSON) |
| Central Database | MS SQL Server, Entity Framework Core |
| Site Storage | SQLite (deployed configs, S&F buffer, event logs) |
| Authentication | Direct LDAP/AD bind (LDAPS/StartTLS), JWT sessions |
| Notifications | Delivered from the central cluster (Email via SMTP/OAuth2-M365 or on-prem Exchange EWS; SMS via Twilio REST); store-and-forwarded from sites |
| Hosting | Windows Server, Windows Service |
| Cluster | Akka.NET Cluster (active/standby, keep-oldest SBR) |
| Logging | Serilog (structured) |
Scale
- Central cluster: 2-node active/standby behind a load balancer.
- Site clusters: 2-node active/standby, headless (no UI).
Repository Layout
| Path | Contents |
|---|---|
src/ |
C#/.NET implementation — one project per component (ZB.MOM.WW.ScadaBridge.<Component>). Solution: ZB.MOM.WW.ScadaBridge.slnx. |
tests/ |
Unit and integration test projects. |
docs/ |
Documentation — docs/requirements/ (high-level + per-component specs, the spec the code implements), docs/components/ (per-component developer reference — how the code works), docs/test_infra/, docs/plans/. |
docker/ |
Primary 8-node cluster topology (2 central + 3 sites × 2 nodes + Traefik) + deploy.sh. |
docker-env2/ |
Minimal second cluster (2 central + 1 site) for exercising Transport (#24) against a real second environment. |
infra/ |
Local test services (MS SQL, LDAP, OPC UA, SMTP, REST API, Traefik). |
deploy/ |
Production/on-host deployment artifacts (e.g. wonder-app-vd03/). |
AkkaDotNet/ |
Akka.NET reference notes. |
Build, Test & Run
# Build the solution
dotnet build ZB.MOM.WW.ScadaBridge.slnx
# Run the tests
dotnet test ZB.MOM.WW.ScadaBridge.slnx
# Bring up the primary local cluster (builds the scadabridge:latest image + recreates containers)
bash docker/deploy.sh # central load balancer at http://localhost:9000
# Drive the system from the CLI (reads ~/.scadabridge/config.json; test user has all roles)
dotnet run --project src/ZB.MOM.WW.ScadaBridge.CLI -- \
--username multi-role --password password template list
See docker/README.md for ports and management commands, and src/ZB.MOM.WW.ScadaBridge.CLI/README.md for the full CLI reference.
Local Test Environments
Two Docker-based cluster topologies are available for local development and testing:
- Primary (
docker/) — Full topology (2 central + 3 sites × 2 nodes + Traefik). Default development target. - Env2 (
docker-env2/) — Minimal sibling stack (2 central + 1 site × 2 nodes + Traefik), runs concurrently with primary on host ports 91XX. Purpose: exercise the Transport (#24) bundle export/import feature against a real second environment.
Both stacks share the infrastructure services in infra/ (MS SQL, LDAP, SMTP, OPC UA, REST API).
Document Map
Requirements
- HighLevelReqs.md — Complete high-level requirements covering all functional areas.
Component Design Documents
| # | Component | Document | Description |
|---|---|---|---|
| 1 | Template Engine | docs/requirements/Component-TemplateEngine.md | Template modeling, inheritance, composition, path-qualified member addressing, override granularity, locking, alarms, native alarm source bindings, flattening, semantic validation, revision hashing, diff calculation, and folder organization (nested folders, drag-drop). |
| 2 | Deployment Manager | docs/requirements/Component-DeploymentManager.md | Central-side deployment pipeline with deployment ID/idempotency, per-instance operation lock, state transition matrix, all-or-nothing site apply, system-wide artifact deployment with per-site status. |
| 3 | Site Runtime | docs/requirements/Component-SiteRuntime.md | Site-side actor hierarchy with explicit supervision strategies, staggered startup, script trust model (constrained APIs), Tell/Ask conventions, concurrency serialization, site-wide Akka stream with per-subscriber backpressure, and a read-only Native Alarm Actor (peer to the computed Alarm Actor) mirroring native OPC UA A&C / MxAccess alarms with site SQLite persistence. |
| 4 | Data Connection Layer | docs/requirements/Component-DataConnectionLayer.md | Common data connection interface (OPC UA, MxGateway, custom), Become/Stash connection actor model, auto-reconnect, immediate bad quality on disconnect, transparent re-subscribe, synchronous write failures, tag path resolution retry, protocol-agnostic address-space browse (with BrowseNext paging, type-info, and the IAddressSpaceSearchable recursive-search seam), a never-trusting OPC UA verify-endpoint probe, and optional read-only native alarm mirroring (IAlarmSubscribableConnection, one alarm feed per connection with snapshot replay). |
| 5 | Central–Site Communication | docs/requirements/Component-Communication.md | Dual transport: Akka.NET ClusterClient (command/control) + gRPC server-streaming (real-time data). 9 message patterns with per-pattern timeouts, SiteStreamGrpcServer/Client, application-level correlation IDs, transport heartbeat config, gRPC keepalive, message ordering, connection failure behavior. The gRPC stream additively carries the read-only native alarm mirror (computed + native OPC UA / MxAccess) via the enriched AlarmStateUpdate. |
| 6 | Store-and-Forward Engine | docs/requirements/Component-StoreAndForward.md | Buffering (transient failures only), fixed-interval retry, parking, async best-effort replication, SQLite persistence at sites. |
| 7 | External System Gateway | docs/requirements/Component-ExternalSystemGateway.md | HTTP/REST + JSON, API key/Basic Auth, per-system timeout, dual call modes (Call/CachedCall), transient/permanent error classification, dedicated blocking I/O dispatcher, ADO.NET connection pooling. |
| 8 | Notification Service | docs/requirements/Component-NotificationService.md | Central-only — manages typed notification-list, SMTP, and SMS definitions; supplies per-type delivery adapters (Email via SMTP with OAuth2 (M365) or Basic Auth, or on-prem Exchange EWS, BCC, plain text; SMS via Twilio REST, per-recipient, outbound-only); delivery performed by the Notification Outbox. |
| 9 | Central UI | docs/requirements/Component-CentralUI.md | Blazor Server with SignalR real-time push, load balancer failover with JWT, all management workflows. Custom-content modal host (DialogService.ShowAsync<T>) with focus-trap/restore; dark-mode CSS-variable token layer ([data-bs-theme="dark"] overriding ZB.MOM.WW.Theme tokens in site.css, localStorage-persisted, SSR no-flash); reusable presentational components OffsetPager, KeysetPager, and DateTimeRangeFilter adopted across report/audit pages. |
| 10 | Security & Auth | docs/requirements/Component-Security.md | Direct LDAP bind (LDAPS/StartTLS), JWT sessions (HMAC-SHA256, 15-min refresh, 30-min idle), role-based authorization (incl. the Operator/Verifier two-person secured-write roles + policies), site-scoped permissions. |
| 11 | Health Monitoring | docs/requirements/Component-HealthMonitoring.md | 30s report interval, 60s offline threshold, monotonic sequence numbers, raw error counts, tag resolution counts, dead letter monitoring. |
| 12 | Site Event Logging | docs/requirements/Component-SiteEventLogging.md | SQLite storage, 30-day retention + 1GB cap, daily purge, paginated remote queries with keyword search. |
| 13 | Cluster Infrastructure | docs/requirements/Component-ClusterInfrastructure.md | Akka.NET cluster, keep-oldest SBR with down-if-alone, min-nr-of-members=1, 2s/10s/15s failure detection, CoordinatedShutdown, automatic dual-node recovery. The ClusterInfrastructure project owns the ClusterOptions config model; the Akka bootstrap/SBR/CoordinatedShutdown wiring lives in the Host. |
| 14 | Inbound API | docs/requirements/Component-InboundAPI.md | POST /api/{methodName}, X-API-Key header, flat JSON, extended type system (Object/List), script-based implementations, failures-only logging. |
| 15 | Host | docs/requirements/Component-Host.md | Single deployable binary, role-based component registration, per-component config binding (Options pattern), readiness gating, dead letter monitoring, Akka.NET bootstrap, ASP.NET Core hosting for central. |
| 16 | Commons | docs/requirements/Component-Commons.md | Namespace/folder convention (Types/Interfaces/Entities/Messages), shared data types, POCOs, repository interfaces, message contracts with additive-only versioning, UTC timestamp convention, the unified read-only alarm condition model (AlarmConditionState/AlarmKind), and native alarm source entities + the IAlarmSubscribableConnection capability seam. |
| 17 | Configuration Database | docs/requirements/Component-ConfigurationDatabase.md | EF Core data access, per-component repositories, unit-of-work, optimistic concurrency on deployment status, audit logging (IAuditService), migration management (incl. the AddNativeAlarmSources migration + native alarm source repository CRUD). |
| 18 | Management Service | docs/requirements/Component-ManagementService.md | Akka.NET ManagementActor on central, ClusterClientReceptionist registration, programmatic access to all admin operations (incl. the MxGateway two-person secured-write handlers — no-self-approval + CAS, MxGateway-only relay — and OPC UA browse/search/verify/cert-trust verbs), CLI interface. |
| 19 | CLI | docs/requirements/Component-CLI.md | Standalone command-line tool, System.CommandLine, HTTP transport via Management API, JSON/table output, mirrors all Management Service operations. |
| 20 | Traefik Proxy | docs/requirements/Component-TraefikProxy.md | Reverse proxy/load balancer fronting central cluster, active node routing via /health/active, automatic failover. |
| 21 | Notification Outbox | docs/requirements/Component-NotificationOutbox.md | Central component ingesting store-and-forwarded notifications into the Notifications audit table, with NotificationOutboxActor singleton dispatcher, per-type delivery adapters, retry/parking, status tracking, daily purge, and delivery KPIs. |
| 22 | Site Call Audit | docs/requirements/Component-SiteCallAudit.md | Central component auditing site cached calls (ExternalSystem.CachedCall/Database.CachedWrite) into the SiteCalls audit table, with SiteCallAuditActor singleton, telemetry ingest, periodic reconciliation, point-in-time KPIs, daily purge, and central→site Retry/Discard relay for parked calls. |
| 23 | Audit Log | docs/requirements/Component-AuditLog.md | New central append-only AuditLog spanning every script-trust-boundary action (outbound API sync+cached, outbound DB sync+cached, notifications, inbound API). Site-local SQLite hot-path append + gRPC telemetry + central reconciliation; combined telemetry packet with Site Call Audit; central direct-write for Notification Outbox dispatch + Inbound API middleware; monthly partitioning, 365-day default retention. |
| 24 | Transport | docs/requirements/Component-Transport.md | Bundle export/import for templates, shared scripts, external systems, central-only artifacts, plus site-scoped config — Sites, site DataConnections, and Instances — reconciled across environments by a BundleNameMap name-mapping subsystem (auto-match + Map wizard step / CLI flags). AES-256-GCM encryption (carry-full-config with encrypted connection secrets); per-conflict resolution with a per-line Myers diff for code fields; real stale-instance enumeration; correlated audit trail. Never touches site runtime nodes. |
| 25 | Script Analysis | docs/requirements/Component-ScriptAnalysis.md | Shared authoritative script-trust analyzer: unified forbidden-API deny-list (ScriptTrustPolicy), fused semantic+syntactic validator (ScriptTrustValidator), Roslyn compile wrapper (RoslynScriptCompiler), and compile-only globals stubs (ScriptCompileSurface/TriggerCompileSurface); consumed by Template Engine, Site Runtime, Inbound API, and Central UI. |
| 26 | KPI History | docs/requirements/Component-KpiHistory.md | Reusable central KPI-history backbone: tall/EAV KpiSample store (central MS SQL), KpiHistoryRecorderActor cluster singleton (kpi-history-recorder, not readiness-gated) sampling DI-registered IKpiSampleSources each minute, bucketed GetRawSeriesAsync + KpiSeriesBucketer query, and a reusable custom-SVG KpiTrendChart. Ships trends for Notification Outbox, Site Call Audit, Audit Log, and Site Health. |
| 27 | DelmiaNotifier | src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/README.md | Standalone external client tool (not deployed to the cluster, not in the Host): a compact Native-AOT (win-x64) console app (WWNotifier.exe) that DELMIA Apriso shells out to per recipe download. POSTs to the Inbound API DelmiaRecipeDownload method (X-API-Key, key from SCADABRIDGE_API_KEY) with connect-failure-only failover across a comma-list of base URLs, and reports the legacy YES/NO + exit-code stdout contract. Drop-in replacement for the legacy WWNotifier (docs/former-api-specs/dnc/). Design: docs/plans/2026-06-26-delmia-recipe-notifier-design.md. |
Shared UI sub-component (not a top-level component): TreeView — reusable hierarchical tree/grid Blazor component used by the Central UI (#9) for the templates folder hierarchy, data-connection browse, and tag pickers.
Component Reference Documentation
The design documents above are the specs (what each component does and why). For developer reference docs that describe how the shipped code works — with real code examples, drawn from src/ and written to the Style Guide — see docs/components/. Reference docs exist for 24 of the 27 components (plus the shared TreeView); ScriptAnalysis (#25), KpiHistory (#26), and DelmiaNotifier (#27) are pending — tracked in docs/plans/2026-07-08-deferred-work-register.md. Indexed in docs/components/README.md.
Reference Documentation
- AkkaDotNet/ — Akka.NET reference notes covering actors, remoting, clustering, persistence, streams, serialization, hosting, testing, and best practices.
- docs/plans/ — Design decision documents from refinement sessions.
Architecture Diagram (Logical)
Site Runtime Actor Hierarchy
%%{init: {'theme':'base', 'themeVariables': {'textColor':'#111111','lineColor':'#555555','edgeLabelBackground':'#ffffff','fontSize':'15px'}}}%%
flowchart TD
DMS["Deployment Manager Singleton<br/>(Cluster Singleton)"]
IA["Instance Actor<br/>(one per deployed, enabled instance)"]
IA2["Instance Actor<br/>( … )"]
MOREIA["… more Instance Actors"]
DMS --> IA
DMS --> IA2
DMS -.-> MOREIA
SA["Script Actor<br/>(coordinator, one per instance script)"]
AA["Alarm Actor<br/>(coordinator, one per alarm definition)"]
MORE1["… more Script /<br/>Alarm Actors"]
IA --> SA
IA --> AA
IA -.-> MORE1
SEA["Script Execution Actor<br/>(short-lived, per invocation)"]
AEA["Alarm Execution Actor<br/>(short-lived, per on-trigger invocation)"]
IA2C["… (Script / Alarm Actors)"]
SA --> SEA
AA --> AEA
IA2 -.-> IA2C
subgraph STREAM["Site-Wide Akka Stream"]
PUB["All Instance Actors"]
STR["Site-Wide Akka Stream<br/>(attribute + alarm state changes)"]
DBG["Debug view<br/>(instance-level filtering)"]
PUB -->|publish| STR
STR -->|subscribe filtered| DBG
end
classDef start fill:#d5e8d4,stroke:#82b366,color:#111111;
classDef proc fill:#dae8fc,stroke:#6c8ebf,color:#111111;
classDef warn fill:#ffe6cc,stroke:#d79b00,color:#111111;
classDef alt fill:#e1d5e7,stroke:#9673a6,color:#111111;
classDef muted fill:#f5f5f5,stroke:#999999,color:#666666;
class DMS,STR alt
class IA,IA2,PUB proc
class SA,AA,DBG start
class SEA,AEA warn
class MOREIA,MORE1,IA2C muted