src/ZB.MOM.WW.ScadaBridge.HealthMonitoring/CentralHealthReportLoop.cs

@@ -9,9 +9,11 @@ namespace ZB.MOM.WW.ScadaBridge.HealthMonitoring;
 /// Periodically builds a SiteHealthReport for the central cluster itself
 /// (siteId = <see cref="CentralSiteId"/>) and feeds it into the local
 /// CentralHealthAggregator so the UI can render central as another card
-/// on /monitoring/health. Only the cluster leader (Primary) generates
+/// on /monitoring/health. Only the active node (Primary = the **oldest Up
-/// reports — the standby's aggregator catches up on failover when it
+/// member**, i.e. the singleton host — <c>IClusterNodeProvider.SelfIsPrimary</c>,
-/// becomes Primary and starts its own loop.
+/// never Akka cluster leadership) generates reports; the standby's aggregator
+/// catches up on failover when it becomes the oldest and its loop starts
+/// reporting.
 /// </summary>
 public class CentralHealthReportLoop : BackgroundService
 {
@@ -41,8 +43,9 @@ public class CentralHealthReportLoop : BackgroundService
     private readonly HealthMonitoringOptions _options;
     private readonly ILogger<CentralHealthReportLoop> _logger;
 
-    // Seeded with Unix-ms so reports from a newly-elected central leader
+    // Seeded with Unix-ms so reports from a node that has newly become active
-    // always sort after reports from any prior leader for siteId="central".
+    // (oldest Up member) always sort after reports from any previously-active
+    // node for siteId="central".
     // The clock is read through the injected TimeProvider so the seeding is
     // deterministically testable.
     private long _sequenceNumber;