Hi Ali, Could you print and include a gellyGraph which results in this error.
Greg > On Jun 27, 2017, at 2:48 PM, rost...@informatik.uni-leipzig.de wrote: > > Dear All, > > I do not understand what the error in the following code can be? > > Graph<GradoopId, Long, NullValue> gellyGraph = ... > > Graph<GradoopId,Summarization.VertexValue<Long>, > Summarization.EdgeValue<NullValue>> g = > gellyGraph.run(new Summarization<GradoopId, Long, > NullValue>()); > > g.getVertices().print(); //this one works fine > g.getEdges().print(); //this one gives the following error > > ... > org.apache.flink.types.NullFieldException: Field 2 is null, but expected to > hold a value. > at > org.apache.flink.api.java.typeutils.runtime.TupleSerializer.serialize(TupleSerializer.java:126) > at > org.apache.flink.api.java.typeutils.runtime.TupleSerializer.serialize(TupleSerializer.java:30) > at > org.apache.flink.runtime.plugable.SerializationDelegate.write(SerializationDelegate.java:56) > at > org.apache.flink.runtime.io.network.api.serialization.SpanningRecordSerializer.addRecord(SpanningRecordSerializer.java:83) > at > org.apache.flink.runtime.io.network.api.writer.RecordWriter.emit(RecordWriter.java:85) > at > org.apache.flink.runtime.operators.shipping.OutputCollector.collect(OutputCollector.java:65) > at > org.apache.flink.runtime.operators.util.metrics.CountingCollector.collect(CountingCollector.java:35) > at > org.apache.flink.graph.library.Summarization$VertexGroupReducer.reduce(Summarization.java:318) > at > org.apache.flink.runtime.operators.GroupReduceDriver.run(GroupReduceDriver.java:131) > at org.apache.flink.runtime.operators.BatchTask.run(BatchTask.java:486) > at > org.apache.flink.runtime.operators.BatchTask.invoke(BatchTask.java:351) > at org.apache.flink.runtime.taskmanager.Task.run(Task.java:584) > at java.lang.Thread.run(Thread.java:748) > > I also tried with different types for EdgeValue. The same error appears. > When I look at the result vertices, everything looks fine. > But the result edges has this problem. > > Any idea? > > Regards, > Ali
