ROW 80 (observability correctness). An unreplicated site published
LocalDbReplicationConnected=false / LocalDbOplogBacklog=0, contradicting the
nullable semantics every doc and the proto already state ("null means no
reading, NOT disconnected with an empty backlog").
Root cause: the replication engine is registered unconditionally and idles
without a peer, so ISyncStatus answers false/0 on a node that was never meant to
replicate, and LocalDbReplicationStatusReporter passed that straight through.
Two consequences: an operator read connected:false on a healthy site as a fault,
and central's null branches — row 33's conditional KPI emission and
sustained-badge anchor exclusion — never received the null they exist for, so
rig site-b/site-c emitted a permanently misleading
localDbReplicationConnected=0 series.
Fix mirrors the SiteEventLogReplicationCheck precedent: the Host evaluates
SiteLocalDbSetup.ReplicationIsConfigured ONCE and passes it to
AddLocalDbReplicationHealthBridge as a third provider; unconfigured
short-circuits the probe to (null, null). HealthMonitoring never reads LocalDb
config itself, and the same captured value now also feeds
SiteEventLogReplicationCheck so the two surfaces cannot disagree.
ISiteHealthCollector.SetLocalDbReplicationStatus widens to bool? — the
non-nullable bool was the type-level root cause (null was inexpressible).
false now means exactly one thing: configured, peer session down = a real fault.
Wire/central/UI needed no change: the proto already carries BoolValue/Int64Value
wrappers and the aggregator + KPI source already branch on null. This makes code
match doc, so no doc claim was weakened.
Watch the trap that caused this: configured-ness is PeerAddress OR ApiKey (only
the dialling half sets a peer address). The pre-existing SiteLocalDbWiringTests
fixture sets ApiKey and IS a replicating node, so its false/0 assertion is
correct and is kept, with a comment saying so; the new
UnreplicatedSiteLocalDbHealthTests fixture is the genuinely-unreplicated one.
ROW 73 (silent loss of self-heal). AkkaHostedService skips
SiteReconciliationActor when no IDeploymentConfigFetcher is resolvable, and that
skip was a lone boot Warning — a node with no self-heal path at all went on
reporting itself perfectly healthy forever.
Adds tri-state SiteHealthReport.StartupReconcilerActive (null = not reported,
i.e. the central self-report or a pre-row-73 site build; true = running;
false = booted without it), latched once at boot by the Host in both branches.
Additive proto field 29 (BoolValue, vendored C# regenerated via
docker/regen-proto.sh centralcontrol; csproj restored, verified empty diff).
The skip branch also raises its log to Error — no configuration makes the
fetcher legitimately absent on a site node — and writes a best-effort
deployment/Error site event so the evidence outlives the boot log.
Central treatment: a "No self-heal" WARNING badge on the site tile, not a
failure. Config still reaches the node via LocalDb replication while it is up;
what it lost is recovery from a deploy that landed while it was down — degraded,
not offline. Only the explicit false is badged (badging null would light up the
whole fleet the moment central is upgraded ahead of the sites), and offline
sites are skipped, matching the replication-backlog badge.
Fail-before evidence: with the row-80 gate behaviourally reverted,
UnreplicatedSite_HealthReport_ReportsNullForBothLocalDbFields fails
"Expected: null / Actual: False" and 3 of the 8 new reporter unit tests fail.
Tests: HealthMonitoring 128, Host 518, CentralUI 1051, Communication 717,
Commons 715, SiteEventLogging 81 — all green.
Phase 4 of the ClusterClient -> gRPC migration deleted the Akka transports
but left the naming behind: `ClusterClientSiteAuditClient` was transport-
agnostic and worked unchanged, so it survived the deletion under a name
that now describes a transport the repo no longer has. Same for a scatter
of doc-comments still framing gRPC as "the new transport" beside an Akka
one that is gone.
Renames it to `SiteCommunicationAuditClient` (and its test file) and
rewrites the stale comments to describe the single transport that exists.
Also tightens CLAUDE.md: drops the self-describing directory listing and
the 27-component enumeration in favour of the non-obvious parts only.
Behaviour-neutral: names and prose only. Recorded as the Phase 4
follow-up in docs/plans/2026-07-22-clusterclient-to-grpc-plan.md.
Phase 1A of the ClusterClient→gRPC migration needs a wire contract for the
seven messages SiteCommunicationActor forwards to /user/central-communication.
This lands the contract and its mapper only — hosting (T1A.2) and the site-side
transport seam (T1A.3) follow.
`Protos/central_control.proto` (package scadabridge.centralcontrol.v1, service
CentralControlService) declares SubmitNotification, QueryNotificationStatus,
IngestAuditEvents, IngestCachedTelemetry, ReconcileSite, ReportSiteHealth and
Heartbeat. Note the direction is the inverse of SiteStreamService: here the site
dials and central serves.
Decisions worth recording:
- The two ingest RPCs IMPORT sitestream.proto and reuse AuditEventBatch /
CachedTelemetryBatch / IngestAck rather than redeclaring them. The site
telemetry actor already builds those messages, so a second copy would fork one
wire contract into two kept in lockstep by hand. ForwardState / IngestedAtUtc
stay off-wire exactly as they are today.
- Heartbeat replies google.protobuf.Empty — it is fire-and-forget and must never
surface a fault onto the heartbeat timer path.
- The three NULLABLE SiteHealthReport collections travel inside single-field
wrapper messages (ConnectionEndpointMapDto / TagQualityMapDto /
NodeStatusListDto). proto3 cannot express presence on repeated/map fields, but
null and empty genuinely differ here — SiteHealthCollector emits
`ClusterNodes: _clusterNodes?.ToList()` and the central health surface reads
null as "not reported", not as "reported empty". Same reasoning drives the
BoolValue/Int64Value/DoubleValue wrappers on LocalDbReplicationConnected,
LocalDbOplogBacklog and the two age gauges, whose docs are explicit that null
is not zero/false.
- ConnectionHealthEnum reserves 0 for UNSPECIFIED instead of mapping Connected
onto it, and the decoder resolves anything unknown to ConnectionHealth.Error.
An unrecognised connection state must not render as "healthy".
- Guid? execution ids travel as "D" strings with empty meaning null; a malformed
non-empty value throws rather than being laundered into "no correlation".
- DateTimeOffset normalizes to a UTC instant (a protobuf Timestamp has no
offset). Lossless in practice — every producer stamps UTC — and documented +
asserted rather than left implicit.
SiteCallDtoMapper gains a ToDto(SiteCall) overload. Its doc comment previously
asserted such a method "would be dead code"; that held only while ClusterClient
was the sole path from IngestCachedTelemetryCommand (which carries SiteCall, not
SiteCallOperational) to central. Comment corrected alongside.
Golden tests round-trip every message through a real protobuf encode/decode —
DTO → proto → bytes → proto → DTO — with a fully-populated case and a
null/empty/minimal case for every optional member. Verified to have teeth by
mutation: dropping a scalar, collapsing an empty nullable collection to absent,
and nulling a gauge each fail a test.
Codegen stays CHECKED IN under CentralControlGrpc/ (protoc segfaults in the
linux_arm64 Docker image); no active <Protobuf> item is committed.
docker/regen-proto.sh is generalized to `regen-proto.sh [sitestream|
centralcontrol|all]` — it now injects the ItemGroup rather than unwrapping a
comment, so it no longer depends on there being exactly one Protobuf line, and
it restores the csproj verbatim on every exit path.
Joseph Doherty