Time for action – changing job priorities and killing a job

Let's explore job priorities by changing them dynamically and watching the result of killing a job.

1. Start a relatively long-running job on the cluster.

   $ hadoop jar hadoop-examples-1.0.4.jar pi 100 1000
   

2. Open another window and submit a second job.

   $ hadoop jar hadoop-examples-1.0.4.jar wordcount test.txt out1
   

3. Open another window and submit a third.

   $ hadoop jar hadoop-examples-1.0.4.jar wordcount test.txt out2
   

4. List the running jobs.

   $ Hadoop job -list
   

   You'll see the following lines on the screen:

   3 jobs currently running
   JobId  State  StartTime  UserName  Priority  SchedulingInfo
   job_201201111540_0005  1  1326325810671  hadoop  NORMAL  NA
   job_201201111540_0006  1  1326325938781  hadoop  NORMAL  NA
   job_201201111540_0007  1  1326325961700  hadoop  NORMAL  NA
   

5. Check the status of the running job.

   $ Hadoop job -status job_201201111540_0005
   

   You'll see the following lines on the screen:

   Job: job_201201111540_0005
   file: hdfs://head:9000...