Gabor Gevay created FLINK-2809:
----------------------------------
Summary: DataSet[Unit] doesn't work
Key: FLINK-2809
URL: https://issues.apache.org/jira/browse/FLINK-2809
Project: Flink
Issue Type: Bug
Components: Scala API
Reporter: Gabor Gevay
Assignee: Gabor Gevay
Priority: Minor
The following code creates a DataSet\[Unit\]:
val env = ExecutionEnvironment.createLocalEnvironment()
val a = env.fromElements(1,2,3)
val b = a.map (_ => ())
b.writeAsText("/tmp/xxx")
env.execute()
This doesn't work, because a VoidSerializer is created, which can't cope with a
BoxedUnit. See exception below.
I'm now thinking about creating a UnitSerializer class.
org.apache.flink.runtime.client.JobExecutionException: Job execution failed.
at
org.apache.flink.runtime.jobmanager.JobManager$$anonfun$receiveWithLogMessages$1.applyOrElse(JobManager.scala:314)
at
scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
at
org.apache.flink.runtime.ActorLogMessages$$anon$1.apply(ActorLogMessages.scala:36)
at
org.apache.flink.runtime.ActorLogMessages$$anon$1.apply(ActorLogMessages.scala:29)
at scala.PartialFunction$class.applyOrElse(PartialFunction.scala:123)
at
org.apache.flink.runtime.ActorLogMessages$$anon$1.applyOrElse(ActorLogMessages.scala:29)
at akka.actor.Actor$class.aroundReceive(Actor.scala:465)
at
org.apache.flink.runtime.jobmanager.JobManager.aroundReceive(JobManager.scala:92)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516)
at akka.actor.ActorCell.invoke(ActorCell.scala:487)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:254)
at akka.dispatch.Mailbox.run(Mailbox.scala:221)
at akka.dispatch.Mailbox.exec(Mailbox.scala:231)
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.ClassCastException: scala.runtime.BoxedUnit cannot be cast
to java.lang.Void
at
org.apache.flink.api.common.typeutils.base.VoidSerializer.serialize(VoidSerializer.java:26)
at
org.apache.flink.runtime.plugable.SerializationDelegate.write(SerializationDelegate.java:51)
at
org.apache.flink.runtime.io.network.api.serialization.SpanningRecordSerializer.addRecord(SpanningRecordSerializer.java:76)
at
org.apache.flink.runtime.io.network.api.writer.RecordWriter.emit(RecordWriter.java:83)
at
org.apache.flink.runtime.operators.shipping.OutputCollector.collect(OutputCollector.java:65)
at
org.apache.flink.runtime.operators.chaining.ChainedMapDriver.collect(ChainedMapDriver.java:78)
at
org.apache.flink.runtime.operators.DataSourceTask.invoke(DataSourceTask.java:177)
at org.apache.flink.runtime.taskmanager.Task.run(Task.java:564)
at java.lang.Thread.run(Thread.java:745)
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
