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
Two genuinely separate single-member clusters sharing the ActorSystem name and
joined only by ClusterClient, so the mesh boundary is exercised over the wire
rather than through an in-process relay: a relay cannot fail for a missing
receptionist extension, an unregistered service, a malformed contact path or a
serialization break, which are the Phase 2 failure modes.
Covers both legs plus the control:
* central SendToAll -> node comm actor -> node EventStream
* node ApplyAck -> central comm actor, through the node's own client
* a node without the receptionist extension receives nothing
Sabotage-verified. Suppressing the node-side EventStream publish and the
outbound ack Tell reddens one leg each. Restoring the receptionist and the
service registration on the control node reddens the control, which is what
proves the control's send is live rather than silently misaddressed.
The control removes the extension AND the RegisterService call, since resolving
the receptionist to register would materialise the extension whose absence is
the point; it falsifies "delivery happens without a receptionist boundary", not
the extension line alone. Recorded in the test.
Also corrects MeshCommActorPathTests: with one node per side, per-node and
singleton registration are indistinguishable here, so the property the dropped
Task 6 assertion covered belongs to live-gate step 8, not to this class.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty