Description
This is a minor issue per se. I had a typo in my script specifying a negative number of reducers for the SleepJob. It results in the exception that is far from the root cause, and appeared as a serious issue with the map-side sort.
2014-06-17 21:42:48,072 INFO [main] org.apache.hadoop.mapred.MapTask: Ignoring exception during close for org.apache.hadoop.mapred.MapTask$NewOutputCollector@972141f java.lang.NullPointerException at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1447) at org.apache.hadoop.mapred.MapTask$NewOutputCollector.close(MapTask.java:700) at org.apache.hadoop.mapred.MapTask.closeQuietly(MapTask.java:1990) at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:774) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:340) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:173) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:415) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1626) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:168) 2014-06-17 21:42:48,075 WARN [main] org.apache.hadoop.mapred.YarnChild: Exception running child : java.lang.IllegalArgumentException at java.nio.ByteBuffer.allocate(ByteBuffer.java:330) at org.apache.hadoop.mapred.SpillRecord.<init>(SpillRecord.java:51) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.mergeParts(MapTask.java:1824) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1484) at org.apache.hadoop.mapred.MapTask$NewOutputCollector.close(MapTask.java:700) at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:770) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:340) at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:173) 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:1626) at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:168)