scadaproj/ZB.MOM.WW.Health

ZB.MOM.WW.Health

Health-check libraries for the ZB.MOM.WW SCADA family (OtOpcUa, MxAccessGateway, ScadaBridge). These are libraries, not a service — each package is linked directly into the consuming application at build time. There is no central health process or network hop; probes run in-process alongside the application.

The library normalizes the three-tier health endpoint convention (/health/ready, /health/active, /healthz) and provides reusable probe implementations so the three sister projects share a common surface without duplicating probe logic.

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Packages

Package	Description	Key Dependencies
ZB.MOM.WW.Health	Core tiers, MapZbHealth extension, canonical JSON writer (ZbHealthWriter), IActiveNodeGate seam, GrpcDependencyHealthCheck reachability probe, and tier-tag constants (ZbHealthTags). No Akka or EF dependency.	Microsoft.AspNetCore.App (framework ref), Grpc.Net.Client
ZB.MOM.WW.Health.Akka	AkkaClusterHealthCheck with a configurable AkkaClusterStatusPolicy (presets: Default three-way / OtOpcUaCompat two-way), ActiveNodeHealthCheck with an optional role filter, and AkkaActiveNodeGate that backs IActiveNodeGate from the cluster member state.	ZB.MOM.WW.Health, Akka.Cluster
ZB.MOM.WW.Health.EntityFrameworkCore	DatabaseHealthCheck<TContext> with CanConnectAsync by default and an optional ProbeQuery delegate for custom connectivity validation.	ZB.MOM.WW.Health, Microsoft.EntityFrameworkCore

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Consumer Matrix

Consumer	ZB.MOM.WW.Health (core)	ZB.MOM.WW.Health.Akka	ZB.MOM.WW.Health.EntityFrameworkCore
OtOpcUa	yes (+ GrpcDependencyHealthCheck for the MxAccessGateway channel)	yes	yes
MxAccessGateway	yes (+ GrpcDependencyHealthCheck for the x86 worker IPC)	—	—
ScadaBridge	yes	yes	yes

MxAccessGateway consumes the core package only — it has no Akka cluster and no EF DbContext. OtOpcUa and ScadaBridge consume all three packages.

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Versioning

All three packages are versioned lockstep from Directory.Build.props. The current release is 0.2.0. A single version bump in Directory.Build.props bumps all three packages simultaneously — consumers should reference the same version for all ZB.MOM.WW.Health packages.

0.2.0 — per-entry data (additive, non-breaking)

• ZbHealthWriter emits an optional "data": { … } object per entry, sourced from the check's HealthCheckResult.Data, only when non-empty — a check that publishes no data produces a byte-identical body to 0.1.0, so every existing consumer is unaffected. Data keys are written verbatim (the camelCase policy applies to the envelope, not to dictionary keys).
• AkkaClusterHealthCheck populates that dictionary with this node's cluster view: leader (omitted while unknown), selfAddress, selfRoles, memberCount, unreachableCount. The startup-safety paths (no ActorSystem, cluster not yet accessible) stay description-only.
• Consumers gain the leader field on a package bump alone — no application code change, provided the app registers the shared AkkaClusterHealthCheck.

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Building and testing

# from ZB.MOM.WW.Health/
dotnet build ZB.MOM.WW.Health.slnx
dotnet test  ZB.MOM.WW.Health.slnx

All three test assemblies run with dotnet test and require no external dependencies — no database and no external cluster (the cluster-data tests form a single-node in-process Akka cluster on a loopback port via Akka.TestKit.Xunit2):

Assembly	Tests
ZB.MOM.WW.Health.Tests	25
ZB.MOM.WW.Health.Akka.Tests	39
ZB.MOM.WW.Health.EntityFrameworkCore.Tests	6
Total	70

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Packing

dotnet pack ZB.MOM.WW.Health.slnx -c Release -o ./artifacts

Produces three .nupkg files in artifacts/:

ZB.MOM.WW.Health.0.2.0.nupkg
ZB.MOM.WW.Health.Akka.0.2.0.nupkg
ZB.MOM.WW.Health.EntityFrameworkCore.0.2.0.nupkg

GeneratePackageOnBuild is off — pack explicitly as above.

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Status

Built at 0.2.0 and published to the Gitea NuGet feed. Adopted by all four apps (OtOpcUa, MxAccessGateway, ScadaBridge, HistorianGateway). Adoption is tracked in the component backlog:

• ~/Desktop/scadaproj/components/health/GAPS.md

Design documentation lives alongside that backlog:

• ~/Desktop/scadaproj/components/health/spec/SPEC.md — normalized three-tier target
• ~/Desktop/scadaproj/components/health/shared-contract/ZB.MOM.WW.Health.md — proposed API
• ~/Desktop/scadaproj/components/health/current-state/ — per-project current state (code-verified)