TaskAttemptID.java
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.mapred;
import java.io.DataInput;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.mapreduce.TaskType;
/**
* TaskAttemptID represents the immutable and unique identifier for
* a task attempt. Each task attempt is one particular instance of a Map or
* Reduce Task identified by its TaskID.
*
* TaskAttemptID consists of 2 parts. First part is the
* {@link TaskID}, that this TaskAttemptID belongs to.
* Second part is the task attempt number. <br>
* An example TaskAttemptID is :
* <code>attempt_200707121733_0003_m_000005_0</code> , which represents the
* zeroth task attempt for the fifth map task in the third job
* running at the jobtracker started at <code>200707121733</code>.
* <p>
* Applications should never construct or parse TaskAttemptID strings
* , but rather use appropriate constructors or {@link #forName(String)}
* method.
*
* @see JobID
* @see TaskID
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class TaskAttemptID extends org.apache.hadoop.mapreduce.TaskAttemptID {
/**
* Constructs a TaskAttemptID object from given {@link TaskID}.
* @param taskId TaskID that this task belongs to
* @param id the task attempt number
*/
public TaskAttemptID(TaskID taskId, int id) {
super(taskId, id);
}
/**
* Constructs a TaskId object from given parts.
* @param jtIdentifier jobTracker identifier
* @param jobId job number
* @param isMap whether the tip is a map
* @param taskId taskId number
* @param id the task attempt number
* @deprecated Use {@link #TaskAttemptID(String, int, TaskType, int, int)}.
*/
@Deprecated
public TaskAttemptID(String jtIdentifier, int jobId, boolean isMap,
int taskId, int id) {
this(jtIdentifier, jobId, isMap ? TaskType.MAP : TaskType.REDUCE, taskId,
id);
}
/**
* Constructs a TaskId object from given parts.
* @param jtIdentifier jobTracker identifier
* @param jobId job number
* @param type the TaskType
* @param taskId taskId number
* @param id the task attempt number
*/
public TaskAttemptID(String jtIdentifier, int jobId, TaskType type,
int taskId, int id) {
this(new TaskID(jtIdentifier, jobId, type, taskId), id);
}
public TaskAttemptID() {
super(new TaskID(), 0);
}
/**
* Downgrade a new TaskAttemptID to an old one
* @param old the new id
* @return either old or a new TaskAttemptID constructed to match old
*/
public static
TaskAttemptID downgrade(org.apache.hadoop.mapreduce.TaskAttemptID old) {
if (old instanceof TaskAttemptID) {
return (TaskAttemptID) old;
} else {
return new TaskAttemptID(TaskID.downgrade(old.getTaskID()), old.getId());
}
}
public TaskID getTaskID() {
return (TaskID) super.getTaskID();
}
public JobID getJobID() {
return (JobID) super.getJobID();
}
@Deprecated
public static TaskAttemptID read(DataInput in) throws IOException {
TaskAttemptID taskId = new TaskAttemptID();
taskId.readFields(in);
return taskId;
}
/** Construct a TaskAttemptID object from given string
* @return constructed TaskAttemptID object or null if the given String is null
* @throws IllegalArgumentException if the given string is malformed
*/
public static TaskAttemptID forName(String str
) throws IllegalArgumentException {
return (TaskAttemptID)
org.apache.hadoop.mapreduce.TaskAttemptID.forName(str);
}
/**
* Returns a regex pattern which matches task attempt IDs. Arguments can
* be given null, in which case that part of the regex will be generic.
* For example to obtain a regex matching <i>all task attempt IDs</i>
* of <i>any jobtracker</i>, in <i>any job</i>, of the <i>first
* map task</i>, we would use :
* <pre>
* TaskAttemptID.getTaskAttemptIDsPattern(null, null, true, 1, null);
* </pre>
* which will return :
* <pre> "attempt_[^_]*_[0-9]*_m_000001_[0-9]*" </pre>
* @param jtIdentifier jobTracker identifier, or null
* @param jobId job number, or null
* @param isMap whether the tip is a map, or null
* @param taskId taskId number, or null
* @param attemptId the task attempt number, or null
* @return a regex pattern matching TaskAttemptIDs
*/
@Deprecated
public static String getTaskAttemptIDsPattern(String jtIdentifier,
Integer jobId, Boolean isMap, Integer taskId, Integer attemptId) {
return getTaskAttemptIDsPattern(jtIdentifier, jobId,
isMap ? TaskType.MAP : TaskType.REDUCE, taskId, attemptId);
}
/**
* Returns a regex pattern which matches task attempt IDs. Arguments can
* be given null, in which case that part of the regex will be generic.
* For example to obtain a regex matching <i>all task attempt IDs</i>
* of <i>any jobtracker</i>, in <i>any job</i>, of the <i>first
* map task</i>, we would use :
* <pre>
* TaskAttemptID.getTaskAttemptIDsPattern(null, null, TaskType.MAP, 1, null);
* </pre>
* which will return :
* <pre> "attempt_[^_]*_[0-9]*_m_000001_[0-9]*" </pre>
* @param jtIdentifier jobTracker identifier, or null
* @param jobId job number, or null
* @param type the {@link TaskType}
* @param taskId taskId number, or null
* @param attemptId the task attempt number, or null
* @return a regex pattern matching TaskAttemptIDs
*/
@Deprecated
public static String getTaskAttemptIDsPattern(String jtIdentifier,
Integer jobId, TaskType type, Integer taskId, Integer attemptId) {
StringBuilder builder = new StringBuilder(ATTEMPT).append(SEPARATOR);
builder.append(getTaskAttemptIDsPatternWOPrefix(jtIdentifier, jobId,
type, taskId, attemptId));
return builder.toString();
}
@Deprecated
static StringBuilder getTaskAttemptIDsPatternWOPrefix(String jtIdentifier
, Integer jobId, TaskType type, Integer taskId, Integer attemptId) {
StringBuilder builder = new StringBuilder();
builder.append(TaskID.getTaskIDsPatternWOPrefix(jtIdentifier
, jobId, type, taskId))
.append(SEPARATOR)
.append(attemptId != null ? attemptId : "[0-9]*");
return builder;
}
}