dohertj2/ScadaBridge
1
0
Fork 0
Code Issues 17 Pull Requests Actions Packages Projects Releases Wiki Activity

feat(cluster): opt-in leader-auto-down strategy - in-repo port of Akka AutoDowning (ScadaBridge#106)

Browse Source 
Adds LeaderAutoDowningProvider (Host/Actors), a line-for-line port of Akka.NET
1.5.62 AutoDowning/AutoDown/AutoDownBase read from the decompiled assembly: the
leader among the reachable members downs a peer unreachable for StableAfter; a
non-leader records it as pending and downs it on becoming leader; reachable-again
or removed members are forgotten; Down/Exiting members are skipped. Its window is
carried under scadabridge.cluster.leader-auto-down.unreachable-after, so no
deprecated auto-down-unreachable-after key is emitted and Akka's boot-time
"keep-majority will be used instead" warning goes away. DownRemovalMargin reads
akka.cluster.down-removal-margin exactly as AutoDowning does (default off).

New SplitBrainResolverStrategy value "leader-auto-down", wired through BuildHocon
and ClusterOptionsValidator. The default stays "auto-down"; auto-down and
keep-oldest HOCON is byte-identical to before. Placed in Host, not
ClusterInfrastructure, per the Code Placement rule (ClusterInfrastructure stays
Akka-free).

Tests: HOCON + validator units; LeaderAutoDownTests ports Akka's AutoDownSpec
cases (leader-only, pending-on-leader-change, losing leadership, reachable again,
removed, Down/Exiting skipped, single Down per member); LeaderAutoDownFailoverTests
clones SbrFailoverTests' oldest-crash and younger-crash cases on a real two-node
cluster plus a test that Akka actually loaded the provider and its downing actor.
Mutation-checked: a provider that never calls Cluster.Down fails both failover
tests; never-downs, leader-check-dropped, reachable-ignored and pending-not-flushed
mutations each fail the unit tests.

Remaining gate before switching the default: the docker failover drill
(DRILL_MODE=active and standby mode) on leader-auto-down.

Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
This commit is contained in:
Joseph Doherty
2026-11-09 16:46:33 -05:00
parent dd99a9f5a5
commit ab561faa43
12 changed files with 805 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files
tests/ZB.MOM.WW.ScadaBridge.ClusterInfrastructure.Tests/ClusterOptionsValidatorTests.cs
+29
View File
@@ -298,4 +298,33 @@ public class ClusterOptionsValidatorTests
Assert.Contains("PartnerProbeIntervalMs", result.FailureMessage);
Assert.Contains("ProbeConnectTimeoutMs", result.FailureMessage);
}
/// <summary>Verifies that the leader-auto-down strategy (ScadaBridge#106) passes validation, case-insensitively.</summary>
/// <param name="strategy">The strategy spelling.</param>
[Theory]
[InlineData("leader-auto-down")]
[InlineData("Leader-Auto-Down")]
public void LeaderAutoDownStrategy_Passes(string strategy)
{
var options = ValidOptions();
options.SplitBrainResolverStrategy = strategy;
options.DownIfAlone = false; // keep-oldest-only knob; inert here, must not block startup
var result = new ClusterOptionsValidator().Validate(null, options);
Assert.True(result.Succeeded, result.FailureMessage);
}
/// <summary>Verifies that the rejection message lists leader-auto-down among the supported strategies.</summary>
[Fact]
public void UnsupportedStrategy_MessageNamesLeaderAutoDown()
{
var options = ValidOptions();
options.SplitBrainResolverStrategy = "leader-autodown";
var result = new ClusterOptionsValidator().Validate(null, options);
Assert.True(result.Failed);
Assert.Contains("'leader-auto-down'", result.FailureMessage);
}
}