MeshPaths.CentralCommunication / .NodeCommunication (the "/user/..." full-path constants) had
ZERO production consumers after the ClusterClient deletion: both gRPC services resolve their
comm actor through ActorRegistry by typed key, never by ActorSelection over a path. Only the
path-probe test still read them, while the class doc went on calling them "the wire contract
of the central↔node boundary" — a claim that stopped being true the moment nothing addressed
an actor across a process boundary by name.
- The two full-path constants are deleted; the two Name constants remain.
- MeshPaths' doc now says what it is (the local actor-naming convention the registry-keyed
services are spawned under) and records what it stopped being, so the next reader does not
re-derive a contract from the file's history.
- MeshCommActorPathTests composes "/user/" + Name itself — the absolute path is that test's
own addressing detail now, not something the product declares. Renamed
Both_mesh_comm_actors_exist_at_their_contract_paths ->
..._are_spawned_under_their_declared_names, because what it still pins is that the two
registration sites actually ran on a real booted node; a rename is now a compile error, so
"contract" was the wrong word for what would break.
- NodeCommunicationActor's summary no longer cross-references the deleted constant or calls
the name an address. CentralCommunicationActor was checked and makes no such claim.
MeshGrpcBoundaryTests replaces the MeshClusterClientBoundaryTests deleted in step 1. Three
self-seeded single-member clusters sharing the ActorSystem name, joined ONLY by gRPC, driving
the REAL CentralCommunicationActor -> MeshGrpcCommandDialer -> Kestrel h2c ->
MeshCommandAuthInterceptor -> NodeCommandGrpcService -> NodeCommunicationActor -> EventStream:
1. No_cross_mesh_Akka_association_forms_between_central_and_either_site — the program's own
point, kept as a test rather than a live-gate note: each cluster stays single-member and
none ever holds another's address as a member.
2. One_dispatch_through_central_reaches_a_node_in_every_cluster_mesh — the fan, with each
site holding its OWN per-cluster PSK, so a dial that selected the wrong cluster's key
would be refused at the far side.
3. Falsifiability_control_a_dial_carrying_the_wrong_cluster_key_delivers_nothing — without
it, (2) cannot distinguish "the gRPC boundary carried it" from "something else in the
process did". The same node then accepts the right key, so the silence is the auth gate
and not a dead endpoint.
All three run fully offline — no Docker fixture — and pass.
Comment sweep across every remaining clusterclient|receptionist hit in src/ and tests/:
the program label becomes "mesh gRPC command plane", and every comment that described the
deleted transport as live now describes what actually runs (Dps = pair-local default,
Grpc = cross-mesh). mesh_transport.proto's header/service comments are reworded; no message,
field or enum is touched — the contract is locked. MeshCommActorPathTests is reshaped rather
than retired: the two paths still exist and still matter, but what a mismatch costs is now a
misleading Unavailable from the gRPC ingress rather than a silently dropped receptionist send.
The only surviving mentions of the old names are the ones that must survive: the fail-closed
rules that name "ClusterClient" as a retired value refused at boot, their tests, and this
test class's own account of what it replaces.
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
Phase 2 Task 6. Both comm actors are now spawned and receptionist-registered:
CentralCommunicationActor from WithOtOpcUaControlPlaneSingletons, and
NodeCommunicationActor from WithOtOpcUaRuntimeActors (before DriverHostActor,
because it is the host's ackRouter under ClusterClient mode; it has no
dependency of its own on the host, since inbound commands travel via the node's
EventStream).
Both are plain WithActors registrations, NOT singletons -- a driver node's
ClusterClient rotates across contact points and must find a live comm actor at
whichever node answers. Both register with the receptionist in BOTH transport
modes: an idle registration costs nothing, whereas registering only under
ClusterClient would mean flipping the flag on a running fleet needs a restart
before anything can be reached, turning a config change back into a deployment.
The coordinator ref is resolved lazily per message (Func<IActorRef?> +
registry.TryGet) so the comm actor never depends on the order in which
Akka.Hosting materialises the singleton proxy relative to this block.
Adds MeshCommActorPathTests, which boots the real two-node host and Identify-
probes both paths. These strings are the wire contract and nothing else asserts
they agree: a rename would compile, pass every unit test, deploy, and deliver
nothing, because a ClusterClient send to an unregistered path is dropped
silently. Sabotage-verified with an actual rename.
DELIBERATELY NOT TESTED, with the reason recorded in the file: that the actors
are per-node rather than singletons. Two discriminators were tried and both were
invalid -- "the path resolves on both nodes" passes under either shape because a
ClusterSingletonManager is also created on every node in the role, and "no
/singleton child" is null even for the KNOWN singleton /user/config-publish, so
Akka.Hosting does not lay them out that way. A sabotage re-registering the actor
via WithSingleton left both green, which is what exposed them. Rather than ship
an assertion that cannot fail, the property is left to the Task 8 boundary test,
where a send only arrives if the target really is registered.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty