org.apache.hadoop.mapred

Class JobID

java.lang.Object

org.apache.hadoop.mapreduce.ID

org.apache.hadoop.mapred.ID

org.apache.hadoop.mapreduce.JobID

org.apache.hadoop.mapred.JobID

All Implemented Interfaces:

Comparable<ID>, Writable, WritableComparable<ID>

@InterfaceAudience.Public
@InterfaceStability.Stable
public class JobID
extends JobID

JobID represents the immutable and unique identifier for the job. JobID consists of two parts. First part represents the jobtracker identifier, so that jobID to jobtracker map is defined. For cluster setup this string is the jobtracker start time, for local setting, it is "local". Second part of the JobID is the job number.
An example JobID is : 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 forName(String) method.

See Also:

TaskID, TaskAttemptID

Field Summary

Fields inherited from class org.apache.hadoop.mapreduce.JobID

idFormat, JOB, JOBID_REGEX

Fields inherited from class org.apache.hadoop.mapreduce.ID

id, SEPARATOR

Constructor Summary

Constructors

Constructor and Description
JobID()
JobID(String jtIdentifier, int id) Constructs a JobID object

Method Summary

Methods

Modifier and Type	Method and Description
static JobID	downgrade(JobID old) Downgrade a new JobID to an old one
static JobID	forName(String str) Construct a JobId object from given string
static String	getJobIDsPattern(String jtIdentifier, Integer jobId) Deprecated.
static JobID	read(DataInput in) Deprecated.

Methods inherited from class org.apache.hadoop.mapreduce.JobID

appendTo, compareTo, equals, getJtIdentifier, hashCode, readFields, toString, write

Methods inherited from class org.apache.hadoop.mapreduce.ID

getId

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

JobID

public JobID(String jtIdentifier,
     int id)

Constructs a JobID object

Parameters:

jtIdentifier - jobTracker identifier

id - job number

JobID

public JobID()

Method Detail

downgrade

public static JobID downgrade(JobID old)

Downgrade a new JobID to an old one

Parameters:

old - a new or old JobID

Returns:

either old or a new JobID build to match old

read

@Deprecated
public static JobID read(DataInput in)
                  throws IOException

Deprecated.

Throws:

IOException

forName

public static JobID forName(String str)
                     throws IllegalArgumentException

Construct a JobId object from given string

Returns:

constructed JobId object or null if the given String is null

Throws:

IllegalArgumentException - if the given string is malformed

getJobIDsPattern

@Deprecated
public static String getJobIDsPattern(String jtIdentifier,
                                 Integer jobId)

Deprecated.

Returns a regex pattern which matches task IDs. Arguments can be given null, in which case that part of the regex will be generic. For example to obtain a regex matching any job run on the jobtracker started at 200707121733, we would use :

 
 JobID.getTaskIDsPattern("200707121733", null);
 

which will return :

 "job_200707121733_[0-9]*" 

Parameters:

jtIdentifier - jobTracker identifier, or null

jobId - job number, or null

Returns:

a regex pattern matching JobIDs