我对Flink外化检查点有两个问题
(Q1)我可以在flink-conf.yaml中设置“state.checkpoints.dir”以使外部检查点正常工作,但是当我从IDE运行flink时如何实现同样的功能呢?我尝试了(http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/state-checkpoints-dir-td17921.html)中提到的GlobalConfiguration方法,但没有运气。我就这样做了:
Configuration cfg =
GlobalConfiguration.loadConfiguration();
cfg.setString("state.checkpoints.dir", "file:///tmp/checkpoints/state");
env.getCheckpointConfig().enableExternalizedCheckpoints(CheckpointConfig.ExternalizedCheckpointCleanup.RETAIN_ON_CANCELLATION);
这是IDE中显示的错误消息:
Exception in thread "main" org.apache.flink.runtime.client.JobExecutionException: Failed to submit job ef7050e2308a4787d983d80f3c07f55c (Long Taxi Rides (checkpointed))
at org.apache.flink.runtime.jobmanager.JobManager.org$apache$flink$runtime$jobmanager$JobManager$$submitJob(JobManager.scala:1325)
at org.apache.flink.runtime.jobmanager.JobManager$$anonfun$handleMessage$1.applyOrElse(JobManager.scala:447)
at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
at org.apache.flink.runtime.LeaderSessionMessageFilter$$anonfun$receive$1.applyOrElse(LeaderSessionMessageFilter.scala:38)
at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
at org.apache.flink.runtime.LogMessages$$anon$1.apply(LogMessages.scala:33)
at org.apache.flink.runtime.LogMessages$$anon$1.apply(LogMessages.scala:28)
at scala.PartialFunction$class.applyOrElse(PartialFunction.scala:123)
at org.apache.flink.runtime.LogMessages$$anon$1.applyOrElse(LogMessages.scala:28)
at akka.actor.Actor$class.aroundReceive(Actor.scala:502)
at org.apache.flink.runtime.jobmanager.JobManager.aroundReceive(JobManager.scala:122)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:526)
at akka.actor.ActorCell.invoke(ActorCell.scala:495)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:257)
at akka.dispatch.Mailbox.run(Mailbox.scala:224)
at akka.dispatch.Mailbox.exec(Mailbox.scala:234)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: java.lang.IllegalStateException: CheckpointConfig says to persist periodic checkpoints, but no checkpoint directory has been configured. You can configure configure one via key 'state.checkpoints.dir'.
at org.apache.flink.runtime.checkpoint.CheckpointCoordinator.<init>(CheckpointCoordinator.java:211)
at org.apache.flink.runtime.executiongraph.ExecutionGraph.enableCheckpointing(ExecutionGraph.java:478)
at org.apache.flink.runtime.executiongraph.ExecutionGraphBuilder.buildGraph(ExecutionGraphBuilder.java:291)
at org.apache.flink.runtime.jobmanager.JobManager.org$apache$flink$runtime$jobmanager$JobManager$$submitJob(JobManager.scala:1277)
... 19 more
Process finished with exit code 1
(Q2)在检查站的文件(https://ci.apache.org/projects/flink/flink-docs-release-1.4/dev/stream/state/checkpointing.html)中,它说“这样,如果你的工作失败,你将有一个检查站从那里恢复。”,取消的工作怎么样?新工作是否会继续使用现有的检查点,还是从自己的检查点开始?
答案 0 :(得分:3)
您可以控制在取消作业时是否删除外部化检查点。如果你想保留它们,你可以这样做:
CheckpointConfig config = env.getCheckpointConfig();
config.enableExternalizedCheckpoints(ExternalizedCheckpointCleanup.RETAIN_ON_CANCELLATION);
有关详细信息,请参阅the docs。
要resume from an externalized checkpoint执行此操作(与从保存点恢复相同):
$ bin/flink run -s :checkpointMetaDataPath [:runArgs]
答案 1 :(得分:2)
第一个问题,使用自定义配置创建本地环境:
val conf = new Configuration()
conf.setString(CoreOptions.CHECKPOINTS_DIRECTORY, "file:///user/flink/checkpoint/storing/")
StreamExecutionEnvironment.createLocalEnvironment(4, conf)
第二个问题,正如大卫所说:
config.enableExternalizedCheckpoints(ExternalizedCheckpointCleanup.RETAIN_ON_CANCELLATION);
答案 2 :(得分:1)
从Eclipse重新设置检查点目录,通常我只是在设置要使用的后端时执行此操作,例如
env.setStateBackend(new FsStateBackend(options.getCheckpointDir()));
重新取消作业 - 检查点目录被删除。如果要在停止(取消)工作后从已知状态恢复,则需要执行保存点。