Description
2015-04-09 03:18:37,002 INFO [TezChild] task.TezTaskRunner: Ignoring the following exception since a previous exception is already registered java.lang.NullPointerException at org.apache.tez.runtime.task.TaskReporter$HeartbeatCallable.access$300(TaskReporter.java:121) at org.apache.tez.runtime.task.TaskReporter.taskFailed(TaskReporter.java:383) at org.apache.tez.runtime.task.TezTaskRunner.sendFailure(TezTaskRunner.java:265) at org.apache.tez.runtime.task.TezTaskRunner.access$600(TezTaskRunner.java:51) at org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable$1.run(TezTaskRunner.java:227) at org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable$1.run(TezTaskRunner.java:171) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:422) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657) at org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable.callInternal(TezTaskRunner.java:171) at org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable.callInternal(TezTaskRunner.java:167) at org.apache.tez.common.CallableWithNdc.call(CallableWithNdc.java:36) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745)
Lot of these messages are seen in logs. Even though it is harmless, this can be very misleading when trying to debug the reason for some other exception.