【发布时间】：2021-12-16 00:51:47
【问题描述】：
我有 2 个与在 Kubernetes 上运行的 StateFun 应用程序的高可用性有关的问题
以下是有关我的设置的详细信息：
- 使用 StateFun v3.1.0
- 检查点存储在 HDFS 上（state.checkpoint-storage: 文件系统）
- 检查点模式为 EXACTLY_ONCE
- 状态后端是 RocksDB 并且启用了增量检查点
1- 我尝试了 Zookeeper 和 Kubernetes HA 设置，结果是一样的（下面的日志来自 Zookeeper HA 环境）。当我杀死 jobmanager pod 时，minikube 会启动另一个 pod，而这个新 pod 在尝试加载最后一个检查点时会失败：
...
2021-12-11 14:25:26,426 INFO org.apache.flink.runtime.jobmaster.JobMaster [] - Initializing job myStatefunApp (00000000000000000000000000000000).
2021-12-11 14:25:26,443 INFO org.apache.flink.runtime.jobmaster.JobMaster [] - Using restart back off time strategy FixedDelayRestartBackoffTimeStrategy(maxNumberRestartAttempts=2147483647, backoffTimeMS=1000) for myStatefunApp (00000000000000000000000000000000).
2021-12-11 14:25:26,516 INFO org.apache.flink.runtime.util.ZooKeeperUtils [] - Initialized DefaultCompletedCheckpointStore in 'ZooKeeperStateHandleStore{namespace='statefun_zk_recovery/my-statefun-app/checkpoints/00000000000000000000000000000000'}' with /checkpoints/00000000000000000000000000000000.
2021-12-11 14:25:26,599 INFO org.apache.flink.runtime.jobmaster.JobMaster [] - Running initialization on master for job myStatefunApp (00000000000000000000000000000000).
2021-12-11 14:25:26,599 INFO org.apache.flink.runtime.jobmaster.JobMaster [] - Successfully ran initialization on master in 0 ms.
2021-12-11 14:25:26,617 INFO org.apache.flink.runtime.scheduler.adapter.DefaultExecutionTopology [] - Built 1 pipelined regions in 1 ms
2021-12-11 14:25:26,626 INFO org.apache.flink.runtime.jobmaster.JobMaster [] - Using job/cluster config to configure application-defined state backend: EmbeddedRocksDBStateBackend{, localRocksDbDirectories=null, enableIncrementalCheckpointing=TRUE, numberOfTransferThreads=1, writeBatchSize=2097152}
2021-12-11 14:25:26,627 INFO org.apache.flink.contrib.streaming.state.EmbeddedRocksDBStateBackend [] - Using predefined options: DEFAULT.
2021-12-11 14:25:26,627 INFO org.apache.flink.contrib.streaming.state.EmbeddedRocksDBStateBackend [] - Using application-defined options factory: DefaultConfigurableOptionsFactory{configuredOptions={state.backend.rocksdb.thread.num=1}}.
2021-12-11 14:25:26,627 INFO org.apache.flink.runtime.jobmaster.JobMaster [] - Using application-defined state backend: EmbeddedRocksDBStateBackend{, localRocksDbDirectories=null, enableIncrementalCheckpointing=TRUE, numberOfTransferThreads=1, writeBatchSize=2097152}
2021-12-11 14:25:26,631 INFO org.apache.flink.runtime.jobmaster.JobMaster [] - Checkpoint storage is set to 'filesystem': (checkpoints "hdfs://hdfs-namenode:8020/tmp/statefun_checkpoints/myStatefunApp")
2021-12-11 14:25:26,712 INFO org.apache.flink.runtime.checkpoint.DefaultCompletedCheckpointStore [] - Recovering checkpoints from ZooKeeperStateHandleStore{namespace='statefun_zk_recovery/my-statefun-app/checkpoints/00000000000000000000000000000000'}.
2021-12-11 14:25:26,724 INFO org.apache.flink.runtime.checkpoint.DefaultCompletedCheckpointStore [] - Found 1 checkpoints in ZooKeeperStateHandleStore{namespace='statefun_zk_recovery/my-statefun-app/checkpoints/00000000000000000000000000000000'}.
2021-12-11 14:25:26,725 INFO org.apache.flink.runtime.checkpoint.DefaultCompletedCheckpointStore [] - Trying to fetch 1 checkpoints from storage.
2021-12-11 14:25:26,725 INFO org.apache.flink.runtime.checkpoint.DefaultCompletedCheckpointStore [] - Trying to retrieve checkpoint 2.
2021-12-11 14:25:26,931 INFO org.apache.flink.runtime.checkpoint.CheckpointCoordinator [] - Restoring job 00000000000000000000000000000000 from Checkpoint 2 @ 1639232587220 for 00000000000000000000000000000000 located at hdfs://hdfs-namenode:8020/tmp/statefun_checkpoints/myStatefunApp/00000000000000000000000000000000/chk-2.
2021-12-11 14:25:27,012 ERROR org.apache.flink.runtime.entrypoint.ClusterEntrypoint [] - Fatal error occurred in the cluster entrypoint.
org.apache.flink.util.FlinkException: JobMaster for job 00000000000000000000000000000000 failed.
at org.apache.flink.runtime.dispatcher.Dispatcher.jobMasterFailed(Dispatcher.java:873) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.dispatcher.Dispatcher.jobManagerRunnerFailed(Dispatcher.java:459) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.dispatcher.Dispatcher.handleJobManagerRunnerResult(Dispatcher.java:436) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.dispatcher.Dispatcher.lambda$runJob$3(Dispatcher.java:415) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at java.util.concurrent.CompletableFuture.uniHandle(Unknown Source) ~[?:?]
at java.util.concurrent.CompletableFuture$UniHandle.tryFire(Unknown Source) ~[?:?]
at java.util.concurrent.CompletableFuture$Completion.run(Unknown Source) ~[?:?]
at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRunAsync(AkkaRpcActor.java:440) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleRpcMessage(AkkaRpcActor.java:208) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.rpc.akka.FencedAkkaRpcActor.handleRpcMessage(FencedAkkaRpcActor.java:77) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.rpc.akka.AkkaRpcActor.handleMessage(AkkaRpcActor.java:158) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:26) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:21) [flink-dist_2.12-1.13.2.jar:1.13.2]
at scala.PartialFunction.applyOrElse(PartialFunction.scala:123) [flink-dist_2.12-1.13.2.jar:1.13.2]
at scala.PartialFunction.applyOrElse$(PartialFunction.scala:122) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.japi.pf.UnitCaseStatement.applyOrElse(CaseStatements.scala:21) [flink-dist_2.12-1.13.2.jar:1.13.2]
at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:171) [flink-dist_2.12-1.13.2.jar:1.13.2]
at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:172) [flink-dist_2.12-1.13.2.jar:1.13.2]
at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:172) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.actor.Actor.aroundReceive(Actor.scala:517) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.actor.Actor.aroundReceive$(Actor.scala:515) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.actor.AbstractActor.aroundReceive(AbstractActor.scala:225) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:592) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.actor.ActorCell.invoke(ActorCell.scala:561) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:258) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.dispatch.Mailbox.run(Mailbox.scala:225) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.dispatch.Mailbox.exec(Mailbox.scala:235) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.dispatch.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.dispatch.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.dispatch.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) [flink-dist_2.12-1.13.2.jar:1.13.2]
at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) [flink-dist_2.12-1.13.2.jar:1.13.2]
Caused by: org.apache.flink.runtime.client.JobInitializationException: Could not start the JobMaster.
at org.apache.flink.runtime.jobmaster.DefaultJobMasterServiceProcess.lambda$new$0(DefaultJobMasterServiceProcess.java:97) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at java.util.concurrent.CompletableFuture.uniWhenComplete(Unknown Source) ~[?:?]
at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(Unknown Source) ~[?:?]
at java.util.concurrent.CompletableFuture.postComplete(Unknown Source) ~[?:?]
at java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source) ~[?:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:?]
at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:?]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) ~[?:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) ~[?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) ~[?:?]
at java.lang.Thread.run(Unknown Source) ~[?:?]
Caused by: java.util.concurrent.CompletionException: java.lang.IllegalStateException: There is no operator for the state 2edd7b5dafb2c271440b25f6da5f4532
at java.util.concurrent.CompletableFuture.encodeThrowable(Unknown Source) ~[?:?]
at java.util.concurrent.CompletableFuture.completeThrowable(Unknown Source) ~[?:?]
at java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source) ~[?:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:?]
at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:?]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) ~[?:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) ~[?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) ~[?:?]
at java.lang.Thread.run(Unknown Source) ~[?:?]
Caused by: java.lang.IllegalStateException: There is no operator for the state 2edd7b5dafb2c271440b25f6da5f4532
at org.apache.flink.runtime.checkpoint.StateAssignmentOperation.checkStateMappingCompleteness(StateAssignmentOperation.java:712) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.checkpoint.StateAssignmentOperation.assignStates(StateAssignmentOperation.java:100) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.checkpoint.CheckpointCoordinator.restoreLatestCheckpointedStateInternal(CheckpointCoordinator.java:1562) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.checkpoint.CheckpointCoordinator.restoreInitialCheckpointIfPresent(CheckpointCoordinator.java:1476) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.scheduler.DefaultExecutionGraphFactory.createAndRestoreExecutionGraph(DefaultExecutionGraphFactory.java:134) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.scheduler.SchedulerBase.createAndRestoreExecutionGraph(SchedulerBase.java:342) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.scheduler.SchedulerBase.<init>(SchedulerBase.java:190) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.scheduler.DefaultScheduler.<init>(DefaultScheduler.java:122) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.scheduler.DefaultSchedulerFactory.createInstance(DefaultSchedulerFactory.java:132) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.jobmaster.DefaultSlotPoolServiceSchedulerFactory.createScheduler(DefaultSlotPoolServiceSchedulerFactory.java:110) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.jobmaster.JobMaster.createScheduler(JobMaster.java:340) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.jobmaster.JobMaster.<init>(JobMaster.java:317) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.jobmaster.factories.DefaultJobMasterServiceFactory.internalCreateJobMasterService(DefaultJobMasterServiceFactory.java:107) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.runtime.jobmaster.factories.DefaultJobMasterServiceFactory.lambda$createJobMasterService$0(DefaultJobMasterServiceFactory.java:95) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at org.apache.flink.util.function.FunctionUtils.lambda$uncheckedSupplier$4(FunctionUtils.java:112) ~[flink-dist_2.12-1.13.2.jar:1.13.2]
at java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source) ~[?:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:?]
at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:?]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) ~[?:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) ~[?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) ~[?:?]
at java.lang.Thread.run(Unknown Source) ~[?:?]
2021-12-11 14:25:27,017 INFO org.apache.flink.runtime.entrypoint.ClusterEntrypoint [] - Shutting StatefulFunctionsClusterEntryPoint down with application status UNKNOWN. Diagnostics Cluster entrypoint has been closed externally..
2021-12-11 14:25:27,021 INFO org.apache.flink.runtime.jobmaster.MiniDispatcherRestEndpoint [] - Shutting down rest endpoint.
2021-12-11 14:25:27,025 INFO org.apache.flink.runtime.blob.BlobServer [] - Stopped BLOB server at 0.0.0.0:6124
2021-12-11 14:25:27,034 INFO org.apache.flink.runtime.jobmaster.MiniDispatcherRestEndpoint [] - Removing cache directory /tmp/flink-web-6c2dafc9-bb7d-489a-9e2d-cf78e3f19b67/flink-web-ui
2021-12-11 14:25:27,035 INFO org.apache.flink.runtime.leaderelection.DefaultLeaderElectionService [] - Stopping DefaultLeaderElectionService.
2021-12-11 14:25:27,035 INFO org.apache.flink.runtime.leaderelection.ZooKeeperLeaderElectionDriver [] - Closing ZooKeeperLeaderElectionDriver{leaderPath='/leader/rest_server_lock'}
2021-12-11 14:25:27,036 INFO org.apache.flink.runtime.jobmaster.MiniDispatcherRestEndpoint [] - Shut down complete.
2021-12-11 14:25:27,036 INFO org.apache.flink.runtime.entrypoint.component.DispatcherResourceManagerComponent [] - Closing components.
2021-12-11 14:25:27,037 INFO org.apache.flink.runtime.leaderretrieval.DefaultLeaderRetrievalService [] - Stopping DefaultLeaderRetrievalService.
2021-12-11 14:25:27,037 INFO org.apache.flink.runtime.leaderretrieval.ZooKeeperLeaderRetrievalDriver [] - Closing ZookeeperLeaderRetrievalDriver{retrievalPath='/leader/dispatcher_lock'}.
2021-12-11 14:25:27,037 INFO org.apache.flink.runtime.leaderretrieval.DefaultLeaderRetrievalService [] - Stopping DefaultLeaderRetrievalService.
2021-12-11 14:25:27,037 INFO org.apache.flink.runtime.leaderretrieval.ZooKeeperLeaderRetrievalDriver [] - Closing ZookeeperLeaderRetrievalDriver{retrievalPath='/leader/resource_manager_lock'}.
2021-12-11 14:25:27,038 INFO org.apache.flink.runtime.leaderelection.DefaultLeaderElectionService [] - Stopping DefaultLeaderElectionService.
2021-12-11 14:25:27,038 INFO org.apache.flink.runtime.leaderelection.ZooKeeperLeaderElectionDriver [] - Closing ZooKeeperLeaderElectionDriver{leaderPath='/leader/dispatcher_lock'}
2021-12-11 14:25:27,039 INFO org.apache.flink.runtime.dispatcher.runner.JobDispatcherLeaderProcess [] - Stopping JobDispatcherLeaderProcess.
2021-12-11 14:25:27,040 INFO org.apache.flink.runtime.resourcemanager.slotmanager.DeclarativeSlotManager [] - Closing the slot manager.
2021-12-11 14:25:27,040 INFO org.apache.flink.runtime.resourcemanager.slotmanager.DeclarativeSlotManager [] - Suspending the slot manager.
2021-12-11 14:25:27,041 INFO org.apache.flink.runtime.leaderelection.DefaultLeaderElectionService [] - Stopping DefaultLeaderElectionService.
2021-12-11 14:25:27,041 INFO org.apache.flink.runtime.leaderelection.ZooKeeperLeaderElectionDriver [] - Closing ZooKeeperLeaderElectionDriver{leaderPath='/leader/resource_manager_lock'}
我认为在使用 StateFun 时无法为 Flink 运算符指定 id（如 here 所述）会导致此问题。虽然它一开始工作正常，但操作员分配了一些随机 id，检查点也很好。重启后，给算子分配其他随机id，当jobmanager（本例中为statefun master）尝试加载状态“2edd7b5dafb2c271440b25f6da5f4532”时，找不到原来分配给它的算子。
有人可以确认我认为是正确的和/或指导我如何让我的 StateFun 应用程序以高可用性运行吗？
要注意的另一件有趣的事情是，在多次重新启动 jobmanager pod 并出现上述异常后，它有时可以通过“Restoring job 0000000000000000000000000000000000 from Checkpoint ...”行以某种方式（？），“没有 master state to恢复”日志 (link) - 这让我不确定它是否真的恢复了，或者它刚刚开始丢弃上次成功检查点的状态。这可能是什么原因造成的？真的从检查点恢复成功了吗？
2- 对于 Kubernetes 部署，StateFun 部署文档 (link) 部署类型用于作业管理器组件。另一方面，Flink 部署文档（Standalone / Kubernetes 部分）（link）使用 Jobmanager 的 Job 类型进行高可用设置（jobmanager-application-ha.yaml 文件）
基本上因为 Kubernetes 会在失败时重新启动 pod，所以可以使用 Job 或 Deployment。但问题是，当我们尝试使用保存点停止作业并使用 Deployment 类型时，Kubernetes 会重新启动 pod，而不管保存点创建成功和成功退出状态 (0)。
在 Kubernetes 上运行时，我们是否不应该使用保存点停止 StateFun 应用程序？我知道相关的错误 (link) - 虽然它似乎已被弃用，但我可以使用保存点取消 - 我们是否应该按照高可用性数据清理部分中的说明删除部署？ (link)
第一个问题的更新：我打开了调试日志记录，并且可以捕获带有异常的会话并连续成功启动。以下来自失败者：
...
2021-12-11 21:55:14,001 DEBUG org.apache.flink.streaming.api.graph.StreamGraphHasherV2 [] - Generated hash '32d5ca33c915e65563a5c7f4d62703ad' for node 'router (my-ingress-1-in)-5' {id: 5, parallelism: 1, user function: }
2021-12-11 21:55:14,001 DEBUG org.apache.flink.streaming.api.graph.StreamGraphHasherV2 [] - Generated hash '33b86fe798648d648b237ddfc986200d' for node 'router (my-ingress-2-in)-4' {id: 4, parallelism: 1, user function: }
2021-12-11 21:55:14,001 DEBUG org.apache.flink.streaming.api.graph.StreamGraphHasherV2 [] - Generated hash 'bd4c3fa1570bbcf606f2dabddd61ed7f' for node 'router (my-ingress-3-in)-6' {id: 6, parallelism: 1, user function: }
这是来自成功的：
2021-12-11 21:55:34,543 DEBUG org.apache.flink.streaming.api.graph.StreamGraphHasherV2 [] - Generated hash 'a1448ecf31ac98d2215c38bfd119abe0' for node 'router (my-ingress-3-in)-5' {id: 5, parallelism: 1, user function: }
2021-12-11 21:55:34,543 DEBUG org.apache.flink.streaming.api.graph.StreamGraphHasherV2 [] - Generated hash '05037ff96baea131d9cf1390846efd98' for node 'router (my-ingress-1-in)-4' {id: 4, parallelism: 1, user function: }
2021-12-11 21:55:34,543 DEBUG org.apache.flink.streaming.api.graph.StreamGraphHasherV2 [] - Generated hash '2edd7b5dafb2c271440b25f6da5f4532' for node 'router (my-ingress-2-in)-6' {id: 6, parallelism: 1, user function: }
似乎两次运行之间生成的哈希计算方式不同。
【问题讨论】：
-
StateFun 内部设置了 Flink JobGraph 的所有算子的确定性 UID，所以这不是这里的问题。您能否提供更多有关您如何部署的信息？您使用的是社区提供的图片还是其他什么？
-
异常读取好像您要从应用程序中删除入口或出口？如果是这种情况，您需要在指定起始快照时使用 --allow-non-restore-state 标志。
-
实际上没有对应用程序进行任何修改，因为没有入口或出口进出 - 因为当主 pod 被 kubernetes 重新创建时，正在使用相同的图像。图像是自定义图像，但将其视为添加到社区图像的 Hadoop 二进制文件，这是唯一的变化 (github.com/apache/flink-statefun-docker/tree/master/…) 由于它是嵌入式 StateFun 应用程序，我按照nightlies.apache.org/flink/flink-statefun-docs-release-3.1/docs/…中的说明进行部署@
-
@Seth 我添加了成功和不成功运行之间不同的调试日志。如果 StateFun 成功地为所有算子设置了确定性 UID，那么在运行之间产生这种不同的哈希生成是否正常？
标签： apache-flink high-availability flink-statefun