"name:version:hashvalue"The hash value is so that if you are talking to multiple clusters, and the job definitions are slightly different, even though they have the same name and version, they will still be uniquely identifiable. This is most important when executing commands against multiple clusters. Many endpoints taking JobId can take an abbreviated JobId. That is, one without a the final colon and hash value.
job_200707121733_0003
, which represents the third job running at the jobtracker started at 200707121733
. Applications should never construct or parse JobID strings, but rather use appropriate constructors or {@link #forName(String)} method. @see TaskID @see TaskAttemptID
job_200707121733_0003
, which represents the third job running at the jobtracker started at 200707121733
. Applications should never construct or parse JobID strings, but rather use appropriate constructors or {@link #forName(String)} method. @see TaskID @see TaskAttemptID
JobId
represents the globally unique identifier for a MapReduce job.
The globally unique nature of the identifier is achieved by using the cluster timestamp from the associated ApplicationId. i.e. start-time of the ResourceManager
along with a monotonically increasing counter for the jobId.
This class has some JPA annotations to allow it to be an entity ID specified via @IdClass.
@author John Mazzitelli
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