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ASF GitHub Bot commented on FLINK-10380: ---------------------------------------- satybald commented on issue #6724: [FLINK-10380] Add precondition for assignToKeyGroup method URL: https://github.com/apache/flink/pull/6724#issuecomment-423422608 another option would be to add try/catch statement for NPE. Try statement doesn't incur any performance issue unless an exception is thrown. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org > Check if key is not nul before assign to group in KeyedStream > ------------------------------------------------------------- > > Key: FLINK-10380 > URL: https://issues.apache.org/jira/browse/FLINK-10380 > Project: Flink > Issue Type: Task > Affects Versions: 1.6.0 > Reporter: Sayat Satybaldiyev > Priority: Minor > Labels: pull-request-available > > If a user creates a KeyedStream and partition by key which might be null, > Flink job throws NullPointerExceptoin at runtime. However, NPE that Flink > throws hard to debug and understand as it doesn't refer to place in Flink job. > *Suggestion:* > Add precondition that checks if the key is not null and throw a descriptive > error if it's a null. > > *Job Example*: > > {code:java} > DataStream<String> stream = env.fromCollection(Arrays.asList("aaa", "bbb")) > .map(x -> (String)null) > .keyBy(x -> x);{code} > > > An error that is thrown: > > {code:java} > Exception in thread "main" > org.apache.flink.runtime.client.JobExecutionException: > java.lang.RuntimeException > at > org.apache.flink.runtime.minicluster.MiniCluster.executeJobBlocking(MiniCluster.java:623) > at > org.apache.flink.streaming.api.environment.LocalStreamEnvironment.execute(LocalStreamEnvironment.java:123) > at org.myorg.quickstart.BuggyKeyedStream.main(BuggyKeyedStream.java:61) > Caused by: java.lang.RuntimeException > at > org.apache.flink.streaming.runtime.io.RecordWriterOutput.pushToRecordWriter(RecordWriterOutput.java:110) > at > org.apache.flink.streaming.runtime.io.RecordWriterOutput.collect(RecordWriterOutput.java:89)16:26:43,110 > INFO org.apache.flink.runtime.rpc.akka.AkkaRpcService - Stopped Akka RPC > service. > at > org.apache.flink.streaming.runtime.io.RecordWriterOutput.collect(RecordWriterOutput.java:45) > at > org.apache.flink.streaming.api.operators.AbstractStreamOperator$CountingOutput.collect(AbstractStreamOperator.java:689) > at > org.apache.flink.streaming.api.operators.AbstractStreamOperator$CountingOutput.collect(AbstractStreamOperator.java:667) > at > org.apache.flink.streaming.api.operators.StreamMap.processElement(StreamMap.java:41) > at > org.apache.flink.streaming.runtime.io.StreamInputProcessor.processInput(StreamInputProcessor.java:202) > at > org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.run(OneInputStreamTask.java:105) > at > org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:300) > at org.apache.flink.runtime.taskmanager.Task.run(Task.java:711) > at java.lang.Thread.run(Thread.java:748) > Caused by: java.lang.NullPointerException > at > org.apache.flink.runtime.state.KeyGroupRangeAssignment.assignToKeyGroup(KeyGroupRangeAssignment.java:59) > at > org.apache.flink.runtime.state.KeyGroupRangeAssignment.assignKeyToParallelOperator(KeyGroupRangeAssignment.java:48) > at > org.apache.flink.streaming.runtime.partitioner.KeyGroupStreamPartitioner.selectChannels(KeyGroupStreamPartitioner.java:63) > at > org.apache.flink.streaming.runtime.partitioner.KeyGroupStreamPartitioner.selectChannels(KeyGroupStreamPartitioner.java:32) > at > org.apache.flink.runtime.io.network.api.writer.RecordWriter.emit(RecordWriter.java:104) > at > org.apache.flink.streaming.runtime.io.StreamRecordWriter.emit(StreamRecordWriter.java:81) > at > org.apache.flink.streaming.runtime.io.RecordWriterOutput.pushToRecordWriter(RecordWriterOutput.java:107) > {code} > ... 10 more -- This message was sent by Atlassian JIRA (v7.6.3#76005)