The hazelcast cluster runs in an application running on Kubernetes. I can't see any traces of partitioning or other problems in the logs. At some point, this exception starts to appear in the logs:
hz.dazzling_morse.partition-operation.thread-1 com.hazelcast.logging.StandardLoggerFactory$StandardLogger: app-name, , , , , - [172.30.67.142]:5701 [app-name] [4.1.5] Executor is shut down.
java.util.concurrent.RejectedExecutionException: Executor is shut down.
at com.hazelcast.scheduledexecutor.impl.operations.AbstractSchedulerOperation.checkNotShutdown(AbstractSchedulerOperation.java:73)
at com.hazelcast.scheduledexecutor.impl.operations.AbstractSchedulerOperation.getContainer(AbstractSchedulerOperation.java:65)
at com.hazelcast.scheduledexecutor.impl.operations.SyncBackupStateOperation.run(SyncBackupStateOperation.java:39)
at com.hazelcast.spi.impl.operationservice.Operation.call(Operation.java:184)
at com.hazelcast.spi.impl.operationexecutor.OperationRunner.runDirect(OperationRunner.java:150)
at com.hazelcast.spi.impl.operationservice.impl.operations.Backup.run(Backup.java:174)
at com.hazelcast.spi.impl.operationservice.Operation.call(Operation.java:184)
at com.hazelcast.spi.impl.operationservice.impl.OperationRunnerImpl.call(OperationRunnerImpl.java:256)
at com.hazelcast.spi.impl.operationservice.impl.OperationRunnerImpl.run(OperationRunnerImpl.java:237)
at com.hazelcast.spi.impl.operationservice.impl.OperationRunnerImpl.run(OperationRunnerImpl.java:452)
at com.hazelcast.spi.impl.operationexecutor.impl.OperationThread.process(OperationThread.java:166)
at com.hazelcast.spi.impl.operationexecutor.impl.OperationThread.process(OperationThread.java:136)
at com.hazelcast.spi.impl.operationexecutor.impl.OperationThread.executeRun(OperationThread.java:123)
at com.hazelcast.internal.util.executor.HazelcastManagedThread.run(HazelcastManagedThread.java:102)
I can't see any particular operation failing, prior to that. I do run some scheduled operations myself, but they are executing inside try-catch blocks and are never throwing.
The consequence is that whenever a node in the cluster restarts no data is replicated to the new node, which eventually renders the entire cluster useless - all data that's supposed to be cached and replicated among nodes disappears.
What could be the cause? How can I get more details about what causes whatever executor hazelcast uses to shut down?