Found while OtOpcUa researched this repo as the model for its own per-cluster
mesh work. Each was verified against the code, not inferred from the doc.
Three transports cross the boundary, not two: ClusterClient, gRPC, and plain
token-gated HTTP for the deploy config fetch (DeploymentConfigEndpoints,
X-Deployment-Token, AllowAnonymous with the per-deployment token as the entire
security boundary).
The gRPC direction is inverted from the data flow. Data moves site to central,
but each SITE hosts the gRPC server and central dials in — MapGrpcService appears
only in the Site branch of Program.cs. There is no gRPC server on central, which
is why the two Ingest* RPCs are dead in practice. Also records the 6-RPC surface
(the doc implied 2), the (site, endpoint) factory key that fixed an arch-review
High, and the vendored-generated-code caveat.
Active/standby is ActiveNodeEvaluator.SelfIsOldestUp — the OLDEST Up member, and
explicitly never cluster.State.Leader, because leadership diverges from singleton
placement permanently after a restart-and-rejoin and both sides claim it during a
partition. The equivalence oldest-Up == singleton placement is the design, and it
was not stated anywhere in this file.
All clusters share one ActorSystem name ("scadabridge", hardcoded at
AkkaHostedService.cs:191); they are separate clusters only by seed partitioning.
Required, not incidental — Akka.Remote address matching means ClusterClient could
not reach a differently-named system. Site nodes also carry two roles, base plus
site-{SiteId}, with singletons scoped to the site-specific one.
Neither inter-cluster transport is authenticated or encrypted: no Akka TLS or
secure cookie, gRPC is h2c, and LocalDbSyncAuthInterceptor gates only the LocalDb
sync path — so the whole SiteStreamService surface, including the two Pull RPCs
returning audit rows, is reachable by anyone who can hit :8083. The boundary
assumes a trusted network; that assumption deserves to be explicit.
Also promotes two things from docs/ into CLAUDE.md because they change decisions:
the default 128 KB Akka frame size with log-frame-size-exceeding off and no custom
serializer (a silent single-message drop that leaves the association healthy), and
the registered two-node keep-oldest total-outage gap, whose own drill has a mode
existing "to make the registered gap observable — not to pretend it is covered."
Committed to a branch rather than main; merge at your discretion.
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
Task 14. A GATE document, not an implementation plan - the plan explicitly wants
Phase 2 planned against post-Phase-1 reality, which means after this record
exists rather than from the original design alone.
Records what Phase 1 actually established (ordering constraints, where
registration lives and why, the fail-closed interceptor, the silent meter
allowlist), what must be ported before anything is deleted (both bespoke
replicator test files, treated as specifications, plus the accepted N5
bounded-duplicate race), and why Phase 2 is a harder risk class than Phase 1:
it REPLACES a working mechanism rather than adding one where none existed,
sf_messages has external side effects, config tables drive deployment, there is
no dual-mechanism period, and the migration is real this time rather than the
usual no-op.
The most important line is an open question, not an answer: choosing
MaxOplogRows / MaxOplogAge / snapshot-resync thresholds for sf_messages write
rates needs a Phase-1 rig SOAK that has not been run. The live gate proved
correctness, not steady-state behaviour over time. Phase 2 should not be planned
without it.
tasks.json finalized: all 15 tasks completed, every deviation from the plan
recorded with its reason.
Claude-Session: https://claude.ai/code/session_01BL2Vu1ESDQ9SCN4gVKkdts
Task 13.
SiteEventLogger's XML doc said 'Not replicated to standby. On failover, the new
active node starts a fresh log.' That is now false and was the exact behaviour
Phase 1 set out to fix.
OperationTrackingOptions.ConnectionString and SiteEventLogOptions.DatabasePath
marked MIGRATION-ONLY: nothing reads them but SiteLocalDbLegacyMigrator, and
they are safe to delete from a config once a node has migrated.
ScadaBridge CLAUDE.md gains a consolidated-site-database entry covering the
GUID/opaque-token contract change, the migration-only keys, the incidental
CWD-outside-the-volume data-loss fix, the fail-closed default-OFF replication
posture, and the fact that ZbTelemetryOptions.Meters is a silent allowlist.
scadaproj CLAUDE.md's LocalDb row goes from 'no app adoption yet' to the honest
current state, per the component-status-honesty convention: ScadaBridge Phase 1
only, on an UNMERGED branch, replication live-proven on the rig's site-a pair
ONLY, default-OFF everywhere else, Phase 2 not started, no other app adopted, no
production deployment replicating.
Claude-Session: https://claude.ai/code/session_01BL2Vu1ESDQ9SCN4gVKkdts
CLAUDE.md: the historian SDK is now owned inside HistorianGateway at
histsdk/ (the separate ~/Desktop/histsdk repo was folded in with history),
so the sister-project list no longer points at a standalone repo.
Also checks in working notes that were sitting untracked in the tree:
deferred.md (remaining deferred work snapshot), ScadaBridge-docs-fixed.md and
ScadaBridge-docs-issues.md (documentation-analysis report output).
Alarm Summary is now live-cache-driven via a transient per-site central
live alarm cache (ISiteAlarmLiveCache) fed by a site-wide, alarm-only
SubscribeSite gRPC stream (seed-then-stream), with the 15s poll retained
as fallback + NotReporting authority. No persisted central alarm store
([PERM]). Updated Component-CentralUI, Component-Communication (new §6.1
+ SubscribeSite RPC), M7 design (T13 delivered note), native-alarms
[PERM] note, stillpending follow-up note, CLAUDE.md, and moved register
row #10 to Resolved (left #22 in place for the sibling branch).
Claude-Session: https://claude.ai/code/session_01MtdgwpEeCUn6cUA5f1LMPj
Update Component-KpiHistory.md with the KpiRollupHourly schema, the third
recorder rollup tick + one-shot backfill, dual raw/rollup purge retention,
raw-vs-rollup query routing by RollupThresholdHours, per-metric gauge-vs-rate
aggregation (KpiMetricAggregationCatalog), the four new options + bounds, and
30d/90d trend windows. Append a Delivered-2026-07-10 note to the m6 design
plan, move register row #22 from Deferred to Resolved, and note rollups in the
CLAUDE.md KPI History bullet. Docs-only; no code changed.
Claude-Session: https://claude.ai/code/session_01MtdgwpEeCUn6cUA5f1LMPj
`dotnet ef migrations add --no-build` scaffolds off the stale prebuilt DLL and
can emit an empty migration; build first and delete the empty Migrations files
if it happens (migrations remove needs a live DB). Placed next to the existing
EF migrations line in Code Organization.
`dotnet test ZB.MOM.WW.ScadaBridge.slnx` silently skips
ZB.MOM.WW.ScadaBridge.CLI.Tests (the one test project not in the slnx), so a
green solution run can hide CLI tests that never compiled. Add the test
command and point at testing the CLI project directly.
Reconcile the Sister Projects section to mirror the peer repos
(MxAccessGateway/HistorianGateway): frame ~/Desktop/scadaproj as the parent
workspace whose CLAUDE.md is the canonical umbrella index that indexes this
repo, point there for the full family list + cross-project map, and add the
previously-missing peers (HistorianGateway, histsdk, scadaproj). Add the
reciprocal "propagate cross-repo changes to the umbrella index" Editing Rule
so an index-recorded fact change here updates the ScadaBridge entry in
../scadaproj/CLAUDE.md in the same change.
infra/ no longer runs scadabridge-ldap (retired); central nodes bind the shared
zb-shared-glauth on 10.100.0.35:3893 (dc=zb,dc=local). Source of truth:
scadaproj/infra/glauth/. test_infra_ldap.md banner-marked SUPERSEDED.
Bulk CommentChecker pass: fills in <param>/<inheritdoc> tags on public
APIs across all 23 src/ projects so the doc-coverage gate is green. Also
adds a Sister Projects section to CLAUDE.md pointing at the MxAccess
Gateway and OtOpcUa sibling repos, and gitignores local credential
captures (*login*.txt) and the wonder-app-vd03 deploy/ artifacts.
- Adds SourceNode varchar(64) NULL to AuditLog, Notifications, and SiteCalls
tables with role-name semantics: node-a/node-b for site rows (qualified by
SourceSiteId), central-a/central-b for central direct-write rows.
- New IX_AuditLog_Node_Occurred (SourceNode, OccurredAtUtc) index.
- Reframes CLAUDE.md from documentation-only to implementation project.
- Adds docs/plans/2026-05-23-audit-source-node.md + tasks.json companion.
LmxProxy is no longer needed. Moved the entire lmxproxy/ workspace, DCL
adapter files, and related docs to deprecated/. Removed LmxProxy registration
from DataConnectionFactory, project reference from DCL, protocol option from
UI, and cleaned up all requirement docs.
Switch site host to WebApplicationBuilder with Kestrel HTTP/2 gRPC server,
add GrpcPort/keepalive config, wire SiteStreamManager as ISiteStreamSubscriber,
expose gRPC ports in docker-compose, add site seed script, update all 10
requirement docs + CLAUDE.md + README.md for the new dual-transport architecture.
The debug view polled every 2s by re-subscribing for full snapshots. Now a
persistent DebugStreamBridgeActor on central subscribes once and receives
incremental Akka stream events from the site, forwarding them to the Blazor
component via callbacks and to the CLI via a new SignalR hub at
/hubs/debug-stream. Adds `debug stream` CLI command with auto-reconnect.
Organize documentation by moving requirements (HighLevelReqs, Component-*,
lmxproxy_protocol) to docs/requirements/ and test infrastructure docs to
docs/test_infra/. Updates all cross-references in README, CLAUDE.md,
infra/README, component docs, and 23 plan files.
Add ActiveNodeHealthCheck that returns 200 only on the Akka.NET cluster
leader, enabling Traefik to route traffic to the active central node and
automatically fail over when the leader changes. Also fixes AkkaClusterHealthCheck
to resolve ActorSystem from AkkaHostedService (was always null via DI).
Replace the CLI's Akka.NET ClusterClient transport with a simple HTTP client
targeting a new POST /management endpoint on the Central Host. The endpoint
handles Basic Auth, LDAP authentication, role resolution, and ManagementActor
dispatch in a single round-trip — eliminating the CLI's Akka, LDAP, and
Security dependencies.
Also fixes DCL ReSubscribeAll losing subscriptions on repeated reconnect by
deriving the tag list from _subscriptionsByInstance instead of _subscriptionIds.
- Add JoeAppEngine folder to OPC UA nodes.json (BTCS, AlarmCntsBySeverity, Scheduler/ScanTime)
- Fix DataConnectionActor: capture Self in PreStart for use from non-actor threads,
preventing Self.Tell failure in Disconnected event handler
- Implement InstanceActor.HandleConnectionQualityChanged to mark attributes Bad on disconnect
- Fix LmxFakeProxy TagMapper to serialize arrays as JSON instead of "System.Int32[]"
- Allow DataType and DataSourceReference updates in TemplateService.UpdateAttributeAsync
- Update test_infra_opcua.md with JoeAppEngine documentation
Joseph Doherty