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Vasia Kalavri commented on FLINK-1587: -------------------------------------- Hi, you can easily reproduce if you have an edge set with an invalid edge ID, as [~andralungu] says. This is a case that shouldn't happen, so I suggest we add a check and throw an exception. This should probably be taken care of in the other 2 degrees methods. [~andralungu] or [~cebe] any of you would like to take care of this? :) -V. > coGroup throws NoSuchElementException on iterator.next() > -------------------------------------------------------- > > Key: FLINK-1587 > URL: https://issues.apache.org/jira/browse/FLINK-1587 > Project: Flink > Issue Type: Bug > Components: Gelly > Environment: flink-0.8.0-SNAPSHOT > Reporter: Carsten Brandt > > I am receiving the following exception when running a simple job that > extracts outdegree from a graph using Gelly. It is currently only failing on > the cluster and I am not able to reproduce it locally. Will try that the next > days. > {noformat} > 02/20/2015 02:27:02: CoGroup (CoGroup at inDegrees(Graph.java:675)) (5/64) > switched to FAILED > java.util.NoSuchElementException > at java.util.Collections$EmptyIterator.next(Collections.java:3006) > at flink.graphs.Graph$CountNeighborsCoGroup.coGroup(Graph.java:665) > at > org.apache.flink.runtime.operators.CoGroupDriver.run(CoGroupDriver.java:130) > at > org.apache.flink.runtime.operators.RegularPactTask.run(RegularPactTask.java:493) > at > org.apache.flink.runtime.operators.RegularPactTask.invoke(RegularPactTask.java:360) > at > org.apache.flink.runtime.execution.RuntimeEnvironment.run(RuntimeEnvironment.java:257) > at java.lang.Thread.run(Thread.java:745) > 02/20/2015 02:27:02: Job execution switched to status FAILING > ... > {noformat} > The error occurs in Gellys Graph.java at this line: > https://github.com/apache/flink/blob/a51c02f6e8be948d71a00c492808115d622379a7/flink-staging/flink-gelly/src/main/java/org/apache/flink/graph/Graph.java#L636 > Is there any valid case where a coGroup Iterator may be empty? As far as I > see there is a bug somewhere. > I'd like to write a test case for this to reproduce the issue. Where can I > put such a test? -- This message was sent by Atlassian JIRA (v6.3.4#6332)