Per-cluster mesh Phase 6 (Task 5). A node carrying a cluster-{ClusterId}
role (RoleParser.IsClusterRole) is in the split topology, where the
Phase 2/3/5 DPS dark-switch branches deliver nothing across the mesh
boundary. SplitTopologyTransportValidator fails host start unless such a
node uses the mesh-crossing transports: MeshTransport:Mode=ClusterClient
always; Telemetry:Mode=Grpc if it has the driver role; TelemetryDial:Mode
=Grpc if it has the admin role. It is a no-op for any node with no
cluster-role (legacy / single-mesh / test). Roles + the three modes are
cross-read from IConfiguration, mirroring ConfigSourceOptionsValidator.
Registered via AddValidatedOptions on MeshTransportOptions with
ValidateOnStart, alongside the sibling validators.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
The per-cluster contact map only gains a key when a row parses, so an
all-malformed cluster has no key at all and is caught by the absent-key arm;
the empty-set guard is defensive/unreachable for the DB producer. Comment-only
(Task 4 code-review minor follow-up).
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Task 3 review: scoping only the rows/enabled DB queries by ClusterId left
the observed set (from Cluster.State.Members) filtered by the driver role
alone. In the mixed-mesh window — DB scoping live via a cluster role, but
the physical Akka mesh not yet split so central still sees foreign members
via gossip — a foreign-cluster driver member stays in observed while its row
is filtered out, hitting the RunningNodeHasNoRow branch, which logs at ERROR.
That traded the Warning-level false positive for a worse Error-level one.
Filter observed by the node's own cluster ROLE too. Extracted the projection
into a static FilterOwnClusterDriverMembers(members, ownClusterRole) so the
membership filter is unit-testable without seeding a live cluster (the actor
harness joins as admin only, so observed is always empty). Sourced at
registration from IClusterRoleInfo.ClusterRole alongside ClusterId. Null role
(legacy, no cluster role) keeps every driver member — reconcile-all, unchanged.
Also clarified the ownClusterId doc wording (non-null-and-non-empty).
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Review follow-ups on the redundancy re-home (Phase 6, Task 2):
- Program.cs: the hasDriver comment claimed IClusterRoleInfo "throws at host
start if this driver node carries no cluster role" — false since the fallback
landed. Rewrite it to describe the cluster-{ClusterId} scope with the driver-role
fallback for legacy single-mesh / not-yet-migrated nodes.
- ClusterRoleInfo.cs: the SubscriberActor comment described RedundancyStateActor as
the "admin-role singleton" — stale. Note it is now a cluster-{ClusterId}-scoped
singleton spawned on every driver node (LeaderChanged stays a no-op here).
- Add a host/registry-level test for the driver-role FALLBACK path (roles ["driver"],
no cluster role) closing the coverage asymmetry — it was proven only in the pure
helper. Asserts the node boots and registers RedundancyStateActorKey, i.e. the boot
the earlier throw-based version would have aborted.
The boot helper now supplies an in-memory IDbContextFactory and a fake IClusterRoleInfo:
Akka.Hosting invokes singleton props factories eagerly at StartAsync, and the admin
ClusterNodeAddressReconciler factory reads both (the latter for its per-cluster reconcile
scope, added by a sibling Phase 6 task) — without them the admin boot NREs.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
After the fleet splits into one Akka mesh per application Cluster, a
ClusterClientReceptionist serves only its own mesh — so the single
fleet-wide client's SendToAll reached only the mesh whose receptionist
answered, leaving every other cluster silently on its old configuration.
Central now holds one ClusterClient per ClusterId and fans SendToAll
across all of them. LoadContactsFromDb selects ClusterId and groups the
receptionist contacts per cluster (keeping the per-row TryParse guard and
the enabled/non-maintenance filter); ContactsLoaded carries
ContactsByCluster; HandleContactsLoaded diffs per cluster (rebuild changed,
stop+drop vanished, warn-don't-create on empty); RebuildClient builds a
per-cluster client under a clusterId-derived actor name. IMeshClusterClientFactory.Create
gained a clusterId parameter so the per-cluster clients get distinct,
diagnosable names. ApplyAck handling and the DPS branch are unchanged; the
deploy path stays payload-free.
Tests: focused unit coverage of the grouping + fan-out (one-client-per-cluster,
fan-out SendToAll to every cluster client) via the recording factory double,
plus the real two-mesh boundary test extended to central + two separate site
meshes proving one dispatch reaches both and a client scoped to one cluster
never crosses into another. Red-before-green verified: crippling the fan-out
to a single client fails the reaches-both-meshes assertion.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Phase 6 splits the fleet into one mesh per Cluster, so an admin (central)
node's Cluster.State.Members shows only its own pair — it no longer sees
site members via gossip. The ClusterNodeAddressReconciler singleton compared
live membership against EVERY ClusterNode row fleet-wide, so post-split every
foreign-cluster row would log EnabledRowNotInCluster forever.
Scope the actor's two DB queries to rows whose ClusterId matches the admin
node's own (IClusterRoleInfo.ClusterId, sourced at registration). A legacy
admin node with no cluster role (null ClusterId) still reconciles the whole
fleet — it genuinely sees every member via gossip. The pure Reconcile
function and AddressMismatchKind semantics are unchanged; scoping lives
entirely in the actor's queries.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Phase 6 splits the single fleet-wide Akka mesh into one 2-node mesh per
application Cluster. RedundancyStateActor was an admin-scoped cluster singleton
that elected ONE fleet-wide driver Primary — but after the split a driver-only
site pair has no admin node in its mesh to host it, so its Primary would never
be elected.
Re-home it: remove the redundancy WithSingleton block from the admin
WithOtOpcUaControlPlaneSingletons set, and add WithOtOpcUaClusterRedundancySingleton,
a singleton spawned from Program.cs's hasDriver branch on EVERY driver node (the
fused central included). It scopes to the node's own cluster-{ClusterId} role when
present, and falls back to the fixed `driver` role otherwise. Each mesh then has
exactly one, electing its own pair-local Primary and publishing redundancy-state
on its own mesh's DistributedPubSub. The election logic (oldest Up driver member)
and the DPS publish are unchanged — they become pair-local after the split.
The driver-role fallback (Decision 2) deliberately does NOT throw when a node has
no cluster role: that is the pre-Phase-6 fleet-wide behavior on a legacy single
mesh, so legacy/harness (TwoNodeClusterHarness: admin,driver) and not-yet-migrated
deployments keep booting unchanged. On a genuinely split 2-node mesh the `driver`
role is already pair-local (the mesh IS the pair), so the fallback is correct in
both worlds. Cluster-scope, when present, additionally survives an accidental
two-mesh merge by keeping one singleton per cluster.
The role scope + driver-role fallback are pinned by unit tests against the
extracted BuildClusterRedundancySingletonOptions helper (the BuildDowningHocon
pattern); admin-removal + driver-registration are pinned behaviorally against a
booted node's ActorRegistry.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Phase 6 Task 1. IClusterRoleInfo gains ClusterRole/ClusterId, derived from
the node's configured AkkaClusterOptions.Roles at construction time (not
live Cluster.State) so the identity is available before the cluster forms.
First cluster-scoped role wins when more than one is configured, logged as
a Warning. Updates the FakeClusterRoleInfo test double in
ServiceCollectionExtensionsTests to satisfy the new interface members.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Phase 6 (per-cluster mesh split) needs nodes to carry a cluster-scoped
role like cluster-SITE-A; RoleParser previously rejected anything
outside the fixed admin/driver/dev set. Adds IsClusterRole/
ClusterIdFromRole plus well-known-role constants, and points the three
duplicate "driver" string literals (RedundancyStateActor,
ClusterNodeAddressReconcilerActor, ServiceCollectionExtensions) at the
new RoleParser.Driver so the value has one source, without renaming
any existing DriverRole symbol.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Plan + task ledger for splitting the single fleet mesh into three 2-node
meshes (central + per-site pairs), cluster-scoped roles + redundancy
singleton, per-cluster ClusterClient, own-cluster reconciler, split-topology
transport validator + flipped defaults, pair-local secrets, and the docker-dev
rig rewrite. Decisions settled with the user 2026-07-24.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Full 12-stream telemetry mesh formed in Grpc mode, AdminUI pill live (data path
proven), kill-and-reconnect recovered a node's stream in ~5s; Dps baseline dials
nothing. Surfaced+validated the ClusterNode.GrpcPort upgrade-backfill gotcha.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Closes two test-completeness gaps flagged in review of the seam-tap commit — the
ScriptedAlarmHostActor and VirtualTagActor hub emits had no test proving the hub
actually receives them.
- ScriptedAlarm_activation_emits_one_Alarm_item_with_matching_payload: spawns the
host with a capturing fake hub, drives a real engine Inactive->Active transition
through the existing ScriptedAlarms harness, and asserts exactly one
TelemetryItem.Alarm carrying the Activated transition.
- VirtualTag_script_log_emits_one_Script_item_with_same_payload: passes a fake hub
via Props + a publisherFactory, drives an evaluator failure, and asserts a
TelemetryItem.Script carrying the SAME ScriptLogEntry instance handed to the
publisher.
To make the VirtualTagActor tap observable, its hub emit moved to the TOP of
PublishLog, before the test-only publisherFactory early-return branch, so the emit
fires on BOTH the production DPS path and the factory path. Production behavior is
unchanged: production passes publisherFactory: null, so it still reaches the DPS
Tell; the emit just moved a couple lines earlier (both are fire-and-forget).
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Each of the four telemetry publish seams now also emits its DPS payload into the
node-local ITelemetryLocalHub (Phase 5), leaving the existing DistributedPubSub
publish untouched:
- driver-health AkkaDriverHealthPublisher -> TelemetryItem.Health
- resilience DriverResilienceStatusPublisherService -> TelemetryItem.Resilience
- alerts ScriptedAlarmHostActor + DriverHostActor (native) -> TelemetryItem.Alarm
- script-logs VirtualTagActor + DpsScriptLogPublisher -> TelemetryItem.Script
DI services take the hub as a required ctor param; actors take an optional
nullable hub threaded through their Props and the real spawn sites
(DriverHostActor <- ServiceCollectionExtensions; VirtualTagActor/ScriptedAlarmHostActor
<- DriverHostActor), so existing test Props constructions keep compiling and simply
do not emit. The hub is a no-op until a gRPC client subscribes, so the emit is safe
on every node.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Scripted-alarm condition state lives in LocalDb (Phase 4); the ConfigDb-backed
Ef store + ScriptedAlarmState table are now dead. Removes the test-harness Ef
fallback (a DB-backed node with no store now skips the alarm host), deletes the
store + entity + model config, and drops the table via migration.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Driver-only nodes now run with NO ConfigDb connection string: config via
FetchAndCache into LocalDb (Phase 3), scripted-alarm condition state in a
replicated LocalDb table, and central persists their deploy acks. DB-reachability
retired from ServiceLevel on DB-less nodes (a healthy site node holds 240/250 with
central SQL down). OpcUaPublish guard split fixes the driver-only address-space
wipe. Live gate PASSED on docker-dev.
Tasks 0-8 + 1b + 10-11 done; Task 9 (drop dead ScriptedAlarmState table) deferred.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Deploy sealed green with 4 DB-less site nodes acking (central persists acks);
ServiceLevel held 240 on a site node with central SQL stopped (survive-alone);
restarted site node booted last-known-good from the LocalDb pointer, no ConfigDb
read; alarm_condition_state table live + replicated. Full record in
2026-07-23-mesh-phase4-live-gate.md. Task 9 (drop dead table) deferred.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
The four driver-only site nodes lose their ConfigDb connection string and hardcode
ConfigSource:Mode=FetchAndCache (Direct is now rejected by the validator for a
driver-only node). Central-1/2 keep ConfigDb + Direct + ConfigServe. Proves the
Phase-4 cut on the rig for the live gate.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
A driver-only node has a null dbFactory but a wired applier; the old combined
guard routed it to the raw-sink fallback that wipes the address space and never
re-materialises. Split the guard so in-hand artifact bytes drive the real
diff-and-apply; a missing artifact abandons the rebuild (keep last-known-good,
#485) instead of wiping.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Task 4+6 code review re-surfaced the OpcUaPublishActor raw-sink wipe on a
null-factory node (the exact #485/#486 defect Task 3 fixes) — Task 3 must land
before any node flips to FetchAndCache. Ordering already enforces this
(3 → 7 → 10 → 11).
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Nullable ConfigDb factory; UpsertNodeDeploymentState no-ops when absent
(central persists acks from the ApplyAck); scripted-alarm condition state
served from the LocalDb store instead of the ConfigDb-backed Ef store.
Combines Phase-4 Tasks 4 + 6. Removes the interim dbFactory! cast.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Task 2 code review surfaced two unguarded ConfigDb sites reachable on a
driver-only node once Tasks 0+1 landed (SpawnScriptedAlarmHost's Ef store,
unconditional UpsertNodeDeploymentState). Task 4 brief now names them + the
dbFactory! removal; Task 6 re-homes the alarm store to LocalDb.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty