NewJobWeightBooster.java
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上传日期:2018-01-08
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- /**
- * 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.conf.Configuration;
- import org.apache.hadoop.conf.Configured;
- /**
- * A {@link WeightAdjuster} implementation that gives a weight boost to new jobs
- * for a certain amount of time -- by default, a 3x weight boost for 60 seconds.
- * This can be used to make shorter jobs finish faster, emulating Shortest Job
- * First scheduling while not starving long jobs.
- */
- public class NewJobWeightBooster extends Configured implements WeightAdjuster {
- private static final float DEFAULT_FACTOR = 3;
- private static final long DEFAULT_DURATION = 5 * 60 * 1000;
- private float factor;
- private long duration;
- public void setConf(Configuration conf) {
- if (conf != null) {
- factor = conf.getFloat("mapred.newjobweightbooster.factor",
- DEFAULT_FACTOR);
- duration = conf.getLong("mapred.newjobweightbooster.duration",
- DEFAULT_DURATION);
- }
- super.setConf(conf);
- }
-
- public double adjustWeight(JobInProgress job, TaskType taskType,
- double curWeight) {
- long start = job.getStartTime();
- long now = System.currentTimeMillis();
- if (now - start < duration) {
- return curWeight * factor;
- } else {
- return curWeight;
- }
- }
- }