[
https://issues.apache.org/jira/browse/SPARK-5206?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14507545#comment-14507545
]
Tathagata Das commented on SPARK-5206:
--------------------------------------
1. Yes, there is no built-in way to persist the latest value of accumulator
and recover again. Since everything dies with the driver, recovering the
value has to be done by the user. If it is not too much data, you could
persist the data to a key-value store after every batch, and then use that
data from recover when restarted.
2. There is not built-in support for upgrade YET. Its in my wish list of
things to add. But its a non-trivial task. Hopefully I will get to it soon.
:)
On Wed, Apr 22, 2015 at 9:24 AM, Zhichao Zhang (JIRA) <j...@apache.org>
> Accumulators are not re-registered during recovering from checkpoint
> --------------------------------------------------------------------
>
> Key: SPARK-5206
> URL: https://issues.apache.org/jira/browse/SPARK-5206
> Project: Spark
> Issue Type: Bug
> Components: Streaming
> Affects Versions: 1.1.0
> Reporter: vincent ye
>
> I got exception as following while my streaming application restarts from
> crash from checkpoit:
> 15/01/12 10:31:06 sparkDriver-akka.actor.default-dispatcher-4 ERROR
> scheduler.DAGScheduler: Failed to update accumulators for ShuffleMapTask(41,
> 4)
> java.util.NoSuchElementException: key not found: 1
> at scala.collection.MapLike$class.default(MapLike.scala:228)
> at scala.collection.AbstractMap.default(Map.scala:58)
> at scala.collection.mutable.HashMap.apply(HashMap.scala:64)
> at
> org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskCompletion$1.apply(DAGScheduler.scala:939)
> at
> org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskCompletion$1.apply(DAGScheduler.scala:938)
> at
> scala.collection.mutable.HashMap$$anonfun$foreach$1.apply(HashMap.scala:98)
> at
> scala.collection.mutable.HashMap$$anonfun$foreach$1.apply(HashMap.scala:98)
> at
> scala.collection.mutable.HashTable$class.foreachEntry(HashTable.scala:226)
> at scala.collection.mutable.HashMap.foreachEntry(HashMap.scala:39)
> at scala.collection.mutable.HashMap.foreach(HashMap.scala:98)
> at
> org.apache.spark.scheduler.DAGScheduler.handleTaskCompletion(DAGScheduler.scala:938)
> at
> org.apache.spark.scheduler.DAGSchedulerEventProcessActor$$anonfun$receive$2.applyOrElse(DAGScheduler.scala:1388)
> at akka.actor.ActorCell.receiveMessage(ActorCell.scala:498)
> at akka.actor.ActorCell.invoke(ActorCell.scala:456)
> at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:237)
> at akka.dispatch.Mailbox.run(Mailbox.scala:219)
> at
> akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:386)
> 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)
> I guess that an Accumulator is registered to a singleton Accumulators in Line
> 58 of org.apache.spark.Accumulable:
> Accumulators.register(this, true)
> This code need to be executed in the driver once. But when the application is
> recovered from checkpoint. It won't be executed in the driver. So when the
> driver process it at
> org.apache.spark.scheduler.DAGScheduler.handleTaskCompletion(DAGScheduler.scala:938),
> It can't find the Accumulator because it's not re-register during the
> recovery.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org
