/**
* 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 org.apache.hadoop.classification.InterfaceAudience.Private;
import org.apache.hadoop.classification.InterfaceStability.Unstable;
/*******************************
* Some handy constants
*
*******************************/
@Private
@Unstable
public interface MRConstants {
//
// Timeouts, constants
//
public static final long COUNTER_UPDATE_INTERVAL = 60 * 1000;
//
// Result codes
//
public static int SUCCESS = 0;
public static int FILE_NOT_FOUND = -1;
/**
* The custom http header used for the map output length.
*/
public static final String MAP_OUTPUT_LENGTH = "Map-Output-Length";
/**
* The custom http header used for the "raw" map output length.
*/
public static final String RAW_MAP_OUTPUT_LENGTH = "Raw-Map-Output-Length";
/**
* The map task from which the map output data is being transferred
*/
public static final String FROM_MAP_TASK = "from-map-task";
/**
* The reduce task number for which this map output is being transferred
*/
public static final String FOR_REDUCE_TASK = "for-reduce-task";
/** Used in MRv1, mostly in TaskTracker code **/
public static final String WORKDIR = "work";
/** Used on by MRv2 */
public static final String APPLICATION_ATTEMPT_ID =
"mapreduce.job.application.attempt.id";
}