We are using Flink version 1.11.2. At times if task managers are restarted for some reason, the job managers throw the exception that I attached here. It is an illegal state exception. We never had this issue with Flink 1.8. It started happening after upgrading to Flink 1.11.2.
Why are the slots not released if it is in a bad state?. The issue doesn't get resolved even if I restart all the task managers. It will get resolved only if I restart Job manager. java.util.concurrent.CompletionException: java.util.concurrent. CompletionException: java.lang.IllegalStateException at org.apache.flink.runtime.jobmaster.slotpool. SlotSharingManager$MultiTaskSlot.lambda$new$0(SlotSharingManager.java:433) at java.base/java.util.concurrent.CompletableFuture.uniHandle( CompletableFuture.java:930) at java.base/java.util.concurrent.CompletableFuture$UniHandle.tryFire( CompletableFuture.java:907) at java.base/java.util.concurrent.CompletableFuture.postComplete( CompletableFuture.java:506) at java.base/java.util.concurrent.CompletableFuture .completeExceptionally(CompletableFuture.java:2088) at org.apache.flink.runtime.concurrent.FutureUtils.lambda$forwardTo$21( FutureUtils.java:1132) at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete( CompletableFuture.java:859) at java.base/java.util.concurrent.CompletableFuture .uniWhenCompleteStage(CompletableFuture.java:883) at java.base/java.util.concurrent.CompletableFuture.whenComplete( CompletableFuture.java:2251) at org.apache.flink.runtime.concurrent.FutureUtils.forward(FutureUtils .java:1100) at org.apache.flink.runtime.jobmaster.slotpool.SlotSharingManager .createRootSlot(SlotSharingManager.java:155) at org.apache.flink.runtime.jobmaster.slotpool.SchedulerImpl .allocateMultiTaskSlot(SchedulerImpl.java:477) at org.apache.flink.runtime.jobmaster.slotpool.SchedulerImpl .allocateSharedSlot(SchedulerImpl.java:311) at org.apache.flink.runtime.jobmaster.slotpool.SchedulerImpl .internalAllocateSlot(SchedulerImpl.java:160) at org.apache.flink.runtime.jobmaster.slotpool.SchedulerImpl .allocateSlotInternal(SchedulerImpl.java:143) at org.apache.flink.runtime.jobmaster.slotpool.SchedulerImpl .allocateSlot(SchedulerImpl.java:113) at org.apache.flink.runtime.executiongraph. SlotProviderStrategy$NormalSlotProviderStrategy.allocateSlot( SlotProviderStrategy.java:115) at org.apache.flink.runtime.scheduler.DefaultExecutionSlotAllocator .lambda$allocateSlotsFor$0(DefaultExecutionSlotAllocator.java:104) at java.base/java.util.concurrent.CompletableFuture.uniComposeStage( CompletableFuture.java:1106) at java.base/java.util.concurrent.CompletableFuture.thenCompose( CompletableFuture.java:2235) at org.apache.flink.runtime.scheduler.DefaultExecutionSlotAllocator .allocateSlotsFor(DefaultExecutionSlotAllocator.java:102) at org.apache.flink.runtime.scheduler.DefaultScheduler.allocateSlots( DefaultScheduler.java:339) at org.apache.flink.runtime.scheduler.DefaultScheduler .allocateSlotsAndDeploy(DefaultScheduler.java:312) at org.apache.flink.runtime.scheduler.strategy.EagerSchedulingStrategy .allocateSlotsAndDeploy(EagerSchedulingStrategy.java:76) at org.apache.flink.runtime.scheduler.strategy.EagerSchedulingStrategy .restartTasks(EagerSchedulingStrategy.java:57) at org.apache.flink.runtime.scheduler.DefaultScheduler .lambda$restartTasks$2(DefaultScheduler.java:265) at java.base/java.util.concurrent.CompletableFuture$UniRun.tryFire( CompletableFuture.java:783) at java.base/java.util.concurrent.CompletableFuture$Completion.run( CompletableFuture.java:478) at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRunAsync( AkkaRpcActor.java:402) at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRpcMessage( AkkaRpcActor.java:195) at org.apache.flink.runtime.rpc.akka.FencedAkkaRpcActor .handleRpcMessage(FencedAkkaRpcActor.java:74) at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleMessage( AkkaRpcActor.java:152) at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:26) at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:21) at scala.PartialFunction$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$WorkQueue.runTask(ForkJoinPool .java:1339) at akka.dispatch.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread .java:107) Caused by: java.util.concurrent.CompletionException: java.lang. IllegalStateException at java.base/java.util.concurrent.CompletableFuture.encodeThrowable( CompletableFuture.java:314) at java.base/java.util.concurrent.CompletableFuture.uniApplyNow( CompletableFuture.java:683) at java.base/java.util.concurrent.CompletableFuture.uniApplyStage( CompletableFuture.java:658) at java.base/java.util.concurrent.CompletableFuture.thenApply( CompletableFuture.java:2094) at org.apache.flink.runtime.jobmaster.slotpool.SlotSharingManager .createRootSlot(SlotSharingManager.java:156) ... 39 more Caused by: java.lang.IllegalStateException at org.apache.flink.util.Preconditions.checkState(Preconditions.java:179 ) at org.apache.flink.runtime.jobmaster.slotpool.SlotSharingManager .tryMarkSlotAsResolved(SlotSharingManager.java:194) at org.apache.flink.runtime.jobmaster.slotpool.SlotSharingManager .lambda$createRootSlot$0(SlotSharingManager.java:160) at java.base/java.util.concurrent.CompletableFuture.uniApplyNow( CompletableFuture.java:680) ... 42 more -- Thanks Josson