-1 We're testing this version on batch jobs with large (600~1000) parallelisms and the following exception messages appear with high frequency:
2021-04-27 21:27:26 org.apache.flink.util.FlinkException: An OperatorEvent from an OperatorCoordinator to a task was lost. Triggering task failover to ensure consistency. Event: '[NoMoreSplitEvent]', targetTask: <task name> - execution #0 at org.apache.flink.runtime.operators.coordination.SubtaskGatewayImpl.lambda$sendEvent$0(SubtaskGatewayImpl.java:81) at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822) at java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:797) at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:442) at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRunAsync(AkkaRpcActor.java:440) at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRpcMessage(AkkaRpcActor.java:208) at org.apache.flink.runtime.rpc.akka.FencedAkkaRpcActor.handleRpcMessage(FencedAkkaRpcActor.java:77) at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleMessage(AkkaRpcActor.java:158) at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:26) at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:21) at scala.PartialFunction$class.applyOrElse(PartialFunction.scala:123) at akka.japi.pf.UnitCaseStatement.applyOrElse(CaseStatements.scala:21) at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:170) at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:171) at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:171) at akka.actor.Actor$class.aroundReceive(Actor.scala:517) at akka.actor.AbstractActor.aroundReceive(AbstractActor.scala:225) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:592) at akka.actor.ActorCell.invoke(ActorCell.scala:561) at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:258) at akka.dispatch.Mailbox.run(Mailbox.scala:225) at akka.dispatch.Mailbox.exec(Mailbox.scala:235) at akka.dispatch.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) at akka.dispatch.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) at akka.dispatch.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) Becket Qin is investigating this issue.
