review(Cluster): record findings + fix snapshot consistency, dispose, stale docs

Code review at HEAD 7286d320. Cluster-001 (SeedFromCurrentState reads from one snapshot), Cluster-003 (HoconLoader double-dispose), Cluster-004 (stale akka.conf header), Cluster-005 (ServiceLevelCalculator tests added to Cluster.Tests). Cluster-002 deferred (no production caller).
2026-06-19 10:22:59 -04:00
parent 6dc74289ce
commit b1946194d6
5 changed files with 242 additions and 8 deletions
@@ -0,0 +1,91 @@
+using Akka.Cluster;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Cluster.Redundancy;
+
+namespace ZB.MOM.WW.OtOpcUa.Cluster.Tests;
+
+/// <summary>
+/// Unit tests for <see cref="ServiceLevelCalculator"/> — the pure ServiceLevel tiering logic.
+/// Moved from ControlPlane.Tests to Cluster.Tests because the type lives in Core.Cluster.
+/// See code-reviews/Cluster/findings.md Cluster-005.
+/// </summary>
+public sealed class ServiceLevelCalculatorTests
+{
+    /// <summary>Non-Up member statuses produce ServiceLevel 0 regardless of other inputs.</summary>
+    [Theory]
+    [InlineData(MemberStatus.Down)]
+    [InlineData(MemberStatus.Removed)]
+    [InlineData(MemberStatus.Exiting)]
+    [InlineData(MemberStatus.Leaving)]
+    public void NotUp_returns_zero(MemberStatus status)
+    {
+        var sl = ServiceLevelCalculator.Compute(new(status,
+            DbReachable: true, OpcUaProbeOk: true, Stale: false, IsDriverRoleLeader: true));
+        sl.ShouldBe((byte)0);
+    }
+
+    /// <summary>Up + DB reachable + probe ok + not stale + not leader = tier 240 (healthy follower).</summary>
+    [Fact]
+    public void Fully_healthy_non_leader_returns_240()
+    {
+        var sl = ServiceLevelCalculator.Compute(new(MemberStatus.Up,
+            DbReachable: true, OpcUaProbeOk: true, Stale: false, IsDriverRoleLeader: false));
+        sl.ShouldBe((byte)240);
+    }
+
+    /// <summary>Up + DB reachable + probe ok + not stale + is leader = tier 250 (healthy leader, +10 bonus).</summary>
+    [Fact]
+    public void Fully_healthy_role_leader_returns_250()
+    {
+        var sl = ServiceLevelCalculator.Compute(new(MemberStatus.Up,
+            DbReachable: true, OpcUaProbeOk: true, Stale: false, IsDriverRoleLeader: true));
+        sl.ShouldBe((byte)250);
+    }
+
+    /// <summary>DB reachable but data stale = tier 200 (stale).</summary>
+    [Fact]
+    public void Db_reachable_but_stale_returns_200()
+    {
+        var sl = ServiceLevelCalculator.Compute(new(MemberStatus.Up,
+            DbReachable: true, OpcUaProbeOk: true, Stale: true, IsDriverRoleLeader: false));
+        sl.ShouldBe((byte)200);
+    }
+
+    /// <summary>DB unreachable AND stale = tier 100 (critically degraded).</summary>
+    [Fact]
+    public void Db_unreachable_and_stale_returns_100()
+    {
+        var sl = ServiceLevelCalculator.Compute(new(MemberStatus.Up,
+            DbReachable: false, OpcUaProbeOk: false, Stale: true, IsDriverRoleLeader: false));
+        sl.ShouldBe((byte)100);
+    }
+
+    /// <summary>OPC UA probe failed while not stale falls through to the catch-all 0.</summary>
+    [Fact]
+    public void Opcua_probe_fail_when_not_stale_returns_zero()
+    {
+        var sl = ServiceLevelCalculator.Compute(new(MemberStatus.Up,
+            DbReachable: true, OpcUaProbeOk: false, Stale: false, IsDriverRoleLeader: false));
+        sl.ShouldBe((byte)0);
+    }
+
+    /// <summary>Joining is treated identically to Up for grading (node is joining the cluster).</summary>
+    [Fact]
+    public void Joining_member_is_treated_like_Up()
+    {
+        var sl = ServiceLevelCalculator.Compute(new(MemberStatus.Joining,
+            DbReachable: true, OpcUaProbeOk: true, Stale: false, IsDriverRoleLeader: false));
+        sl.ShouldBe((byte)240);
+    }
+
+    /// <summary>Leader bonus is clamped to 255 even if a hypothetical basis would overflow.</summary>
+    [Fact]
+    public void Result_is_clamped_to_255()
+    {
+        // basis 240 + 10 = 250, already within byte range; confirms Clamp is in path
+        var sl = ServiceLevelCalculator.Compute(new(MemberStatus.Up,
+            DbReachable: true, OpcUaProbeOk: true, Stale: false, IsDriverRoleLeader: true));
+        ((int)sl).ShouldBeLessThanOrEqualTo(255);
+    }
+}