org.apache.hadoop.mapred
Class JobID

java.lang.Object
  extended by org.apache.hadoop.mapreduce.ID
      extended by org.apache.hadoop.mapred.ID
          extended by org.apache.hadoop.mapreduce.JobID
              extended by 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
JobID()
           
JobID(String jtIdentifier, int id)
          Constructs a JobID object
 
Method Summary
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


Copyright © 2012 Apache Software Foundation. All Rights Reserved.