Joseph Doherty
a61e041e58
Promotes the two apps' private replacements for ActiveNodeHealthCheck into one shared primitive, and retires the leader/RoleLeader selection they were written to avoid. Both Akka consumers had already hand-rolled a replacement rather than use this package (ScadaBridge OldestNodeActiveHealthCheck, OtOpcUa ClusterPrimaryHealthCheck), so the entire active-node surface here — ActiveNodeHealthCheck, AkkaActiveNodeGate — had ZERO consumers. It was not merely unused: it was avoided, twice, for the same reason. Leadership is address-ordered (host, then port) and has no relationship to time; singleton placement is age-ordered. The two agree on a freshly-formed cluster, which is why single-node and happy-path tests never caught it. They diverge permanently after any restart: the restarted node rejoins as the youngest but keeps its address, so if it holds the lower address it becomes leader while the singletons — and all the work they own — stay on the other node. New ClusterActiveNode is the single implementation: oldest Up member, optional role scope, plus role-preference resolution for a fused node that must answer for the role its singletons are pinned to. ActiveNodeHealthCheck and AkkaActiveNodeGate both delegate to it, so an endpoint gate and the /health/active probe an orchestrator routes by cannot disagree. BREAKING (behaviour, not signature): - Selection is by age, not leadership. - The role-filtered mode no longer reports Healthy for a node LACKING the role. That "not applicable => Healthy" made the tier answer 200 on every node and silently broke leader-pinning (lmxopcua#494); it is now Unhealthy by default, overridable via NoActiveRoleStatus. This case is reachable, not defensive — OtOpcUa's RoleParser admits dev-only and cluster-role-only nodes. - Identity compares UniqueAddress, so a node restarted on the same host:port is correctly a different member during the overlap. Results now carry activeRole/selfAddress/activeNode in the 0.2.0 per-entry data object, so a standby reports WHO is active and a dashboard can render a pair from either node's payload alone. Tests: 45 Akka (was 39), 76 total. The age-vs-address divergence is pinned against a real two-node cluster built so the oldest member is not the lowest-addressed one, with a fixture sanity check so it cannot pass for the wrong reason.
57 lines
2.2 KiB
C#
57 lines
2.2 KiB
C#
using ZB.MOM.WW.Health.Akka;
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namespace ZB.MOM.WW.Health.Akka.Tests;
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/// <summary>
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/// Covers <see cref="ClusterActiveNode.ResolveActiveRole"/> — which role a node competes for. Pure,
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/// so no cluster is needed; the age-ordering half of the rule is pinned in
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/// <see cref="ClusterActiveNodeTests"/> against a real two-node cluster.
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/// </summary>
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public sealed class ActiveRoleResolutionTests
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{
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[Fact]
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public void EmptyPreference_IsUnscoped()
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{
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// Unscoped: every Up member competes for one active slot (the ScadaBridge central pattern).
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Assert.Null(ClusterActiveNode.ResolveActiveRole(["admin", "driver"], []));
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}
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[Fact]
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public void FusedNode_AnswersForTheHighestPrecedenceRoleItCarries()
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{
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Assert.Equal(
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"admin",
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ClusterActiveNode.ResolveActiveRole(["admin", "driver", "cluster-MAIN"], ["admin", "driver"]));
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}
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[Fact]
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public void SingleRoleNode_AnswersForThatRole()
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{
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// The regression the OtOpcUa fix existed for: under the old role-filtered check every
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// driver-only node reported Healthy — "or not a role member" — so all of them called
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// themselves active and no consumer could find the active node of a site cluster. lmxopcua#494.
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Assert.Equal(
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"driver",
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ClusterActiveNode.ResolveActiveRole(["driver", "cluster-SITE-A"], ["admin", "driver"]));
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}
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[Fact]
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public void PreferenceOrderWins_NotTheOrderTheNodeListsItsRoles()
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{
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// Self-role order is incidental (it comes from config parsing); precedence must come from the
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// caller's list alone, or a fused node's answer would depend on how its roles were spelled.
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Assert.Equal(
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"admin",
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ClusterActiveNode.ResolveActiveRole(["driver", "admin"], ["admin", "driver"]));
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}
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[Fact]
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public void NodeCarryingNoneOfThePreferredRoles_ResolvesToNull()
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{
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// Reachable, not merely defensive: OtOpcUa's RoleParser admits a dev-only or cluster-role-only
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// node. Such a node owns no active work — the health check maps this to Unhealthy so it stays
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// out of the active pool.
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Assert.Null(ClusterActiveNode.ResolveActiveRole(["dev", "cluster-MAIN"], ["admin", "driver"]));
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}
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}
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