I have a pair of 35M of links from 117K nodes and ran pagerank job on 3 node m2.2xlarge EMR cluster. Initially I got out of memory error in the reduce phase so I increased the JVM size and then now I am getting the following error (and this happens in one reduce job and the other 3 completes without any error):
2015-01-04 03:44:40,349 WARN [main] org.apache.hadoop.mapred.YarnChild: Exception running child : org.apache.pig.backend.executionengine.ExecException: ERROR 0: Exception while executing (Name: topic_ranks: New For Each(false,false,false)[bag] - scope-42 Operator Key: scope-42): org.apache.pig.backend.executionengine.ExecException: ERROR 0: Exception while executing [POUserFunc (Name: POUserFunc(datafu.pig.linkanalysis.PageRank)[bag] - scope-33 Operator Key: scope-33) children: null at []]: java.lang.NullPointerException
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.processInput(PhysicalOperator.java:289)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.getNextTuple(POForEach.java:242)
at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapReduce$Reduce.runPipeline(PigGenericMapReduce.java:464)
at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapReduce$Reduce.processOnePackageOutput(PigGenericMapReduce.java:432)
at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapReduce$Reduce.reduce(PigGenericMapReduce.java:412)
at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapReduce$Reduce.reduce(PigGenericMapReduce.java:256)
at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:171)
at org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java:635)
at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:390)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:167)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1548)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:162)
Any idea how to resolve this issue? I used Hadoop 2.4.0 and Pig 0.12.0.
I have a pair of 35M of links from 117K nodes and ran pagerank job on 3 node m2.2xlarge EMR cluster. Initially I got out of memory error in the reduce phase so I increased the JVM size and then now I am getting the following error (and this happens in one reduce job and the other 3 completes without any error):
2015-01-04 03:44:40,349 WARN [main] org.apache.hadoop.mapred.YarnChild: Exception running child : org.apache.pig.backend.executionengine.ExecException: ERROR 0: Exception while executing (Name: topic_ranks: New For Each(false,false,false)[bag] - scope-42 Operator Key: scope-42): org.apache.pig.backend.executionengine.ExecException: ERROR 0: Exception while executing [POUserFunc (Name: POUserFunc(datafu.pig.linkanalysis.PageRank)[bag] - scope-33 Operator Key: scope-33) children: null at []]: java.lang.NullPointerException
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.processInput(PhysicalOperator.java:289)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.getNextTuple(POForEach.java:242)
at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapReduce$Reduce.runPipeline(PigGenericMapReduce.java:464)
at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapReduce$Reduce.processOnePackageOutput(PigGenericMapReduce.java:432)
at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapReduce$Reduce.reduce(PigGenericMapReduce.java:412)
at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapReduce$Reduce.reduce(PigGenericMapReduce.java:256)
at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:171)
at org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java:635)
at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:390)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:167)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1548)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:162)
Any idea how to resolve this issue? I used Hadoop 2.4.0 and Pig 0.12.0.