/*
* 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.File;
/**
* TaskTrackerInstrumentation defines a number of instrumentation points
* associated with TaskTrackers. By default, the instrumentation points do
* nothing, but subclasses can do arbitrary instrumentation and monitoring at
* these points.
*
* TaskTrackerInstrumentation interfaces are associated uniquely with a
* TaskTracker. We don't want an inner class here, because then subclasses
* wouldn't have direct access to the associated TaskTracker.
*
**/
class TaskTrackerInstrumentation {
protected final TaskTracker tt;
public TaskTrackerInstrumentation(TaskTracker t) {
tt = t;
}
/**
* invoked when task attempt t succeeds
* @param t
*/
public void completeTask(TaskAttemptID t) { }
public void timedoutTask(TaskAttemptID t) { }
public void taskFailedPing(TaskAttemptID t) { }
/**
* Called just before task attempt t starts.
* @param stdout the file containing standard out of the new task
* @param stderr the file containing standard error of the new task
*/
public void reportTaskLaunch(TaskAttemptID t, File stdout, File stderr) { }
/**
* called when task t has just finished.
* @param t
*/
public void reportTaskEnd(TaskAttemptID t) {}
}