Akka.Cluster.Hosting's WithClustering enables an SBR downing provider by default
(applies SplitBrainResolverOption.Default when ClusterOptions.SplitBrainResolver is
null), which reads the pre-existing akka.conf keep-oldest block. So the cluster was
NOT running NoDowning before Critical 1 and hard-crash failover already worked — the
typed KeepOldestOption is reinforcing/explicit-in-code, not the sole activator.
Corrects the inaccurate 'HOCON inert / NoDowning / never fails over' framing in:
- ServiceCollectionExtensions.BuildClusterOptions XML comment
- akka.conf split-brain-resolver comment
- docs/Redundancy.md Split-brain section
- SplitBrainResolverActivationTests summary + assertion message (+ method rename)
No code revert (the typed option is correct belt-and-suspenders). Cluster.Tests 29/29.
Surfaced by the #9 hard-kill failover negative control.
The split-brain-resolver HOCON block in akka.conf was inert — nothing
registered a downing provider, so the cluster ran Akka's default NoDowning:
a hard-crashed node was never downed, cluster singletons + the driver
role-leader never failed over, and a partition left both redundancy sides
at ServiceLevel 240 indefinitely.
Activate the resolver via the typed ClusterOptions.SplitBrainResolver
(KeepOldestOption { DownIfAlone = true }) in a new testable
BuildClusterOptions helper. keep-oldest + down-if-alone is correct for a
2-node warm-redundancy pair. HOCON keeps stable-after (typed option can't
express it) + a cross-reference comment. Deterministic unit guard added;
end-to-end verified the resolved ActorSystem config carries the provider
and stable-after survives the HOCON/Hosting merge. Redundancy.md corrected.
Hard-kill failover integration test tracked as a follow-up (effort-M harness).
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).
All five suppressed advisories are now resolved at baseline/resolved versions,
so every NuGetAuditSuppress is removed repo-wide:
- System.Security.Cryptography.Xml (GHSA-37gx-xxp4-5rgx / GHSA-w3x6-4m5h-cxqf)
-> fixed by the .NET 10 baseline (10.0.6)
- OPCFoundation Opc.Ua.Core (GHSA-h958-fxgg-g7w3) -> fixed at resolved 1.5.378.106
Two were still live and are now patched via direct security pins:
- OpenTelemetry.Api 1.9.0 -> 1.15.3 (GHSA-g94r-2vxg-569j) pinned in Cluster;
Runtime/ControlPlane/AdminUI + tests inherit via project reference
- Tmds.DBus.Protocol 0.20.0 -> 0.21.3 (GHSA-xrw6-gwf8-vvr9) pinned in Client.UI
Also correct the Historian sidecar runtime comments (x86 -> x64, matching the
csproj PlatformTarget). Solution audit: 0 vulnerable packages; full build clean.
Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.
Joseph Doherty