Hadoop provides a command line utility for changing the priority of running job. There are total 5 different priority level are there. These priority levels are listed below:
VERY_HIGH
HIGH
NORMAL
LOW
VERY_LOW
We can change the priority of the running hadoop job syntax is shown below:
VERY_HIGH
HIGH
NORMAL
LOW
VERY_LOW
We can change the priority of the running hadoop job syntax is shown below:
hadoop job -set-priority <job-id> <priority>
Example:
hadoop job -set-priority job_20170111540_64444 VERY_HIGH
From the names of the priority levels, it is quite obvious that highest priority is given to the jobs whose priority level is VERY_HIGH and least priority is given to the jobs whose priority level is VERY_LOW.
Priority in Map Reduce Program:
In order to set priority for a job on Hadoop 1 cluster, you can use the following example:
-> SET mapred.job.priority=<priority_value>;
In order to set priority for a job on Hadoop 2 cluster, you can use the following example:
-> SET mapreduce.job.priority=<priority_value>;
Priority in Pig Program:
The below property is used to set the job priority is Pig Programming.
grunt> SET job.priority 'high'
The following <priority_value> values are supported:
very_low, low, normal, high, very_high
Priority for Hive Query:
In order to set priority for a HIVE query on Hadoop 1 cluster, you can use the following example:
hive> SET mapred.job.priority=VERY_HIGH;
In order to set priority for a HIVE query on Hadoop 2 cluster, you can use the following example:
hive> SET mapreduce.job.priority=VERY_HIGH;
If you are facing any problems in changing the priority of the hadoop jobs, then please comment here.