[KYLIN-1581] NPE in Job engine when execute MR job

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: v1.5.0, v1.5.1
• Fix Version/s: v1.5.2
• Assignee: Shao Feng Shi
• Reporter: Shao Feng Shi
• Created: 13/Apr/16 08:12
• Updated: 26/May/16 09:16
• Resolved: 14/Apr/16 11:28

Description

An NPE throws when executing a job step:

org.apache.kylin.job.exception.ExecuteException: java.lang.NullPointerException
at org.apache.kylin.job.execution.AbstractExecutable.execute(AbstractExecutable.java:124)
at org.apache.kylin.job.impl.threadpool.DefaultScheduler$JobRunner.run(DefaultScheduler.java:124)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at org.apache.kylin.engine.mr.common.MapReduceExecutable.onExecuteStart(MapReduceExecutable.java:77)
at org.apache.kylin.job.execution.AbstractExecutable.execute(AbstractExecutable.java:105)
at org.apache.kylin.job.execution.DefaultChainedExecutable.doWork(DefaultChainedExecutable.java:50)
at org.apache.kylin.job.execution.AbstractExecutable.execute(AbstractExecutable.java:114)
... 4 more

It looks like that, this step had been executed before, maybe after a restart it wants to check the job's status from hadoop, but the recorded job id wasn't found in hadoop, caused this NPE.