docs(cluster): self-first seed ordering replaces the self-form fallback

docs/Redundancy.md's bootstrap section is rewritten around the mechanism that is actually in force: which of Akka's two bootstrap processes runs is decided by whether seed-nodes[0] is this node's own address, so the ORDER of Cluster:SeedNodes is the fix, not a timer. Adds the per-process table, the shipped self-first example, why the validator is conditional (site nodes are not seeds) and why it matches PublicHostname rather than the 0.0.0.0 bind address. The retirement is documented rather than erased: a new subsection explains that a watchdog outside the join handshake cannot tell "no seed answered" from "a seed answered and the join is in flight", and the ea45ace1 live-gate finding is kept verbatim as the evidence that produced that conclusion (InitJoinAck at 10:49:05, old incarnation retired 10:49:06, watchdog fired 10:49:15, second cluster). The watchdog's own earlier PASS is kept too — it did pass what it was gated on. Also: a live gate for the NEW mechanism is registered as outstanding (not re-drilled on the docker-dev rig since the swap), and the plan doc that shipped the watchdog gets a superseded banner rather than an edit, so the execution record and its Task 8 finding stay readable. Ripple: CLAUDE.md cluster section, docs/Configuration.md + docs/v2/Cluster.md + docs/ServiceHosting.md SeedNodes entries, the per-cluster-mesh design doc's two "CLOSED by SelfFormAfter" notes, and mesh-program Phase 6 (which had this convergence queued — now marked done early) + Phase 7's live-gate name.
2026-07-22 07:46:02 -04:00
parent 3f24d4d6bf
commit 9af935f237
9 changed files with 132 additions and 81 deletions
@@ -56,6 +56,7 @@ The host joins an Akka.NET cluster bound to the address in `appsettings.json::Cl
 }
 ```

+- `SeedNodes` is **ordered**: a node listed in its own seed list must be entry 0, since Akka only lets `seed-nodes[0]` form a new cluster. `AkkaClusterOptionsValidator` fails startup otherwise — see [Redundancy.md § Bootstrap: self-first seed ordering](Redundancy.md#bootstrap-self-first-seed-ordering).
 - `WithOtOpcUaClusterBootstrap` (in `OtOpcUa.Cluster`) loads the embedded HOCON (split-brain resolver, pinned dispatcher, failure detector tuning) and overlays remote endpoint + cluster options.
 - All cluster singletons + per-node actors live on this single ActorSystem — there is no second Akka instance.