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 2 Task 3. Central-side end of the boundary: routes every central->node
command out over DPS or ClusterClient per MeshTransport:Mode, and forwards
inbound ApplyAcks to the deploy coordinator singleton (Forward, not Tell, so
the coordinator sees the node rather than this relay).
Three things here are load-bearing and easy to get wrong later:
SendToAll, never Send. Today's DPS publish reaches EVERY DriverHostActor and
the node side has no ClusterId or node filter to compensate -- scoping happens
later, inside the artifact. ClusterClient.Send delivers to exactly ONE
registered actor, so it would deploy to a single node while every other node
silently kept its old config, and the deployment could still seal green.
Sabotage-verified: swapping to Send reddens exactly that one test.
Exactly ONE ClusterClient, fleet-wide. A receptionist serves its whole cluster,
so SendToAll reaches every registered node-comm actor in the mesh regardless of
which contact point was dialled. One client per application Cluster -- the
shape Phase 6 wants -- would fan each command out once per cluster while the
fleet is still one mesh: N x duplicate DispatchDeployment and ApplyAck. Marked
TODO(Phase 6).
The contact set does NOT scope delivery. Excluding a maintenance-mode node from
the contacts does not stop it receiving commands; it still receives them, as it
does under today's broadcast. The filter is about which receptionists are worth
dialling, not about who gets the message. Stated in the code because the
opposite is the natural assumption.
Also carries the sister project's shipped fixes: per-row address parsing so one
malformed ClusterNode cannot abort the refresh and leave the contact set
half-built (regression test orders the bad row FIRST), the cache entry cleared
before recreate so a failed create cannot leave commands routing into a
stopping actor, and a Status.Failure handler so a DB outage is a Warning rather
than a silent debug-level unhandled message.
Two test-harness bugs found and fixed while writing this, both mine: SubscribeAck
goes to the SENDER (so the mediator subscribe needed an explicit sender), and
EventFilter matches case-INSENSITIVELY, so a "was NOT" filter also caught this
actor's own "was not created" warning.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty