Description
While running few PIG scripts against Hadoop 2.0, I see consistently see ConcurrentModificationException
at java.util.HashMap$HashIterator.remove(HashMap.java:811) at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POPartialAgg.aggregate(POPartialAgg.java:365) at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POPartialAgg.aggregateSecondLevel(POPartialAgg.java:379) at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POPartialAgg.getNext(POPartialAgg.java:203) at org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.processInput(PhysicalOperator.java:308) at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POLocalRearrange.getNext(POLocalRearrange.java:263) at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.runPipeline(PigGenericMapBase.java:283) at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.map(PigGenericMapBase.java:278) at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.map(PigGenericMapBase.java:64) at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144) at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:729) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:334) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:158) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:396) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1441) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:153)
It looks like there is rawInputMap is being modified while elements are removed from it.