feat(mesh-phase4): retire DB-reachability from ServiceLevel on DB-less nodes

Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
2026-07-23 11:55:43 -04:00
parent 5c40908a55
commit 9565827275
4 changed files with 223 additions and 11 deletions
@@ -580,6 +580,143 @@ public sealed class OpcUaPublishActorTests : RuntimeActorTestBase
        AwaitAssert(() => publisher.Levels.ShouldContain((byte)250), TimeSpan.FromSeconds(2));
    }

+    // ── Per-cluster mesh Phase 4: DB-less driver-only nodes ─────────────────────────────────────
+    // A driver-only node has no ConfigDb (LocalDb is its config store), so there is no DB to probe.
+    // Such nodes run with dbHealthProbe: null + dbLess: true and must still publish the full
+    // survive-alone ServiceLevel (240 follower / 250 Primary) — DbReachable is treated as a
+    // constant true because the in-process LocalDb can never be "unreachable"; only snapshot
+    // staleness demotes.
+
+    /// <summary>DB-less, member Up, snapshot fresh, follower (non-Primary) → 240. No probe wired,
+    /// no DbHealthStatus ever arrives; the DB-less branch must still reach full service.</summary>
+    [Fact]
+    public void DbLess_healthy_follower_publishes_240()
+    {
+        var publisher = new RecordingPublisher();
+        var local = NodeId.Parse("db-less-follower");
+        var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(
+            serviceLevel: publisher, localNode: local, dbLess: true,
+            staleWindow: TimeSpan.FromSeconds(30)));
+
+        actor.Tell(new RedundancyStateChanged(
+            Nodes: new[]
+            {
+                new NodeRedundancyState(local, RedundancyRole.Secondary,
+                    IsClusterLeader: false, IsDriverPrimary: false, DateTime.UtcNow),
+            },
+            CorrelationId.NewId()));
+
+        AwaitAssert(() => publisher.Levels.ShouldContain((byte)240),
+            duration: TimeSpan.FromMilliseconds(500));
+    }
+
+    /// <summary>DB-less, member Up, snapshot fresh, Primary → 250 (basis 240 + 10 Primary bonus).</summary>
+    [Fact]
+    public void DbLess_healthy_primary_publishes_250()
+    {
+        var publisher = new RecordingPublisher();
+        var local = NodeId.Parse("db-less-primary");
+        var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(
+            serviceLevel: publisher, localNode: local, dbLess: true,
+            staleWindow: TimeSpan.FromSeconds(30)));
+
+        actor.Tell(new RedundancyStateChanged(
+            Nodes: new[]
+            {
+                new NodeRedundancyState(local, RedundancyRole.Primary,
+                    IsClusterLeader: true, IsDriverPrimary: true, DateTime.UtcNow),
+            },
+            CorrelationId.NewId()));
+
+        AwaitAssert(() => publisher.Levels.ShouldContain((byte)250),
+            duration: TimeSpan.FromMilliseconds(500));
+    }
+
+    /// <summary>DB-less, snapshot stale (entry.AsOfUtc older than the stale window) → 200. Staleness
+    /// is derived from snapshot age ALONE (no DB-health term), so a DB-less node still demotes to 200
+    /// when it is running behind on config.</summary>
+    [Fact]
+    public void DbLess_stale_snapshot_publishes_200()
+    {
+        var publisher = new RecordingPublisher();
+        var local = NodeId.Parse("db-less-stale");
+        var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(
+            serviceLevel: publisher, localNode: local, dbLess: true,
+            staleWindow: TimeSpan.FromSeconds(2)));
+
+        actor.Tell(new RedundancyStateChanged(
+            Nodes: new[]
+            {
+                new NodeRedundancyState(local, RedundancyRole.Secondary,
+                    IsClusterLeader: false, IsDriverPrimary: false,
+                    DateTime.UtcNow - TimeSpan.FromMinutes(1)),
+            },
+            CorrelationId.NewId()));
+
+        AwaitAssert(() => publisher.Levels.ShouldContain((byte)200),
+            duration: TimeSpan.FromMilliseconds(500));
+    }
+
+    /// <summary>DB-less, Detached → 0. The Detached / missing-entry guard runs ABOVE the DB-less
+    /// branch, so a DB-less node that detaches still fails closed to 0. Goes healthy (250) first so
+    /// the transition down to 0 is observable (not dedup'd against the initial 0).</summary>
+    [Fact]
+    public void DbLess_detached_publishes_0()
+    {
+        var publisher = new RecordingPublisher();
+        var local = NodeId.Parse("db-less-detached");
+        var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(
+            serviceLevel: publisher, localNode: local, dbLess: true,
+            staleWindow: TimeSpan.FromSeconds(30)));
+
+        actor.Tell(new RedundancyStateChanged(
+            Nodes: new[]
+            {
+                new NodeRedundancyState(local, RedundancyRole.Primary,
+                    IsClusterLeader: true, IsDriverPrimary: true, DateTime.UtcNow),
+            },
+            CorrelationId.NewId()));
+        AwaitAssert(() => publisher.Levels.ShouldContain((byte)250),
+            duration: TimeSpan.FromMilliseconds(500));
+
+        actor.Tell(new RedundancyStateChanged(
+            Nodes: new[]
+            {
+                new NodeRedundancyState(local, RedundancyRole.Detached,
+                    IsClusterLeader: false, IsDriverPrimary: false, DateTime.UtcNow),
+            },
+            CorrelationId.NewId()));
+
+        AwaitAssert(() => publisher.Levels.ShouldContain((byte)0),
+            duration: TimeSpan.FromMilliseconds(500));
+    }
+
+    /// <summary>Regression: a DB-BACKED node (probe wired + DbHealthStatus reachable, dbLess default
+    /// false) is unchanged — it still computes 240 via the calculator path. Proves the new DB-less
+    /// branch did not disturb the existing DB-backed seam.</summary>
+    [Fact]
+    public void DbBacked_node_unchanged_still_publishes_240()
+    {
+        var publisher = new RecordingPublisher();
+        var local = NodeId.Parse("db-backed-node");
+        var probe = Sys.ActorOf(Akka.Actor.Props.Create(() =>
+            new StubDbHealth(new DbHealthProbeActor.DbHealthStatus(true, DateTime.UtcNow, null))));
+        var actor = Sys.ActorOf(OpcUaPublishActor.PropsForTests(
+            serviceLevel: publisher, localNode: local, dbHealthProbe: probe));
+
+        actor.Tell(new DbHealthProbeActor.DbHealthStatus(true, DateTime.UtcNow, null));
+        actor.Tell(new RedundancyStateChanged(
+            Nodes: new[]
+            {
+                new NodeRedundancyState(local, RedundancyRole.Secondary,
+                    IsClusterLeader: false, IsDriverPrimary: false, DateTime.UtcNow),
+            },
+            CorrelationId.NewId()));
+
+        AwaitAssert(() => publisher.Levels.ShouldContain((byte)240),
+            duration: TimeSpan.FromMilliseconds(500));
+    }
+
    /// <summary>Stub DB-health probe actor that answers <see cref="DbHealthProbeActor.GetStatus"/>
    /// with a fixed status, so the calculator path is deterministic without a real timer.</summary>
    private sealed class StubDbHealth : Akka.Actor.ReceiveActor