| /** |
| * 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.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| /** |
| * Class responsible for modeling the resource consumption of running tasks. |
| * |
| * For now, we just do temp space for maps |
| * |
| * There is one ResourceEstimator per JobInProgress |
| * |
| */ |
| class ResourceEstimator { |
| |
| //Log with JobInProgress |
| private static final Log LOG = LogFactory.getLog( |
| "org.apache.hadoop.mapred.ResourceEstimator"); |
| |
| private long completedMapsInputSize; |
| private long completedMapsOutputSize; |
| |
| private int completedMapsUpdates; |
| final private JobInProgress job; |
| private int threshholdToUse; |
| |
| public ResourceEstimator(JobInProgress job) { |
| this.job = job; |
| threshholdToUse = job.desiredMaps()/ 10; |
| } |
| |
| protected synchronized void updateWithCompletedTask(TaskStatus ts, |
| TaskInProgress tip) { |
| |
| //-1 indicates error, which we don't average in. |
| if(tip.isMapTask() && ts.getOutputSize() != -1) { |
| completedMapsUpdates++; |
| |
| completedMapsInputSize+=(tip.getMapInputSize()+1); |
| completedMapsOutputSize+=ts.getOutputSize(); |
| |
| if(LOG.isDebugEnabled()) { |
| LOG.debug("completedMapsUpdates:"+completedMapsUpdates+" "+ |
| "completedMapsInputSize:"+completedMapsInputSize+" " + |
| "completedMapsOutputSize:"+completedMapsOutputSize); |
| } |
| } |
| } |
| |
| /** |
| * @return estimated length of this job's total map output |
| */ |
| protected synchronized long getEstimatedTotalMapOutputSize() { |
| if(completedMapsUpdates < threshholdToUse) { |
| return 0; |
| } else { |
| long inputSize = job.getInputLength() + job.desiredMaps(); |
| //add desiredMaps() so that randomwriter case doesn't blow up |
| //the multiplication might lead to overflow, casting it with |
| //double prevents it |
| long estimate = Math.round(((double)inputSize * |
| completedMapsOutputSize * 2.0)/completedMapsInputSize); |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("estimate total map output will be " + estimate); |
| } |
| return estimate; |
| } |
| } |
| |
| /** |
| * @return estimated length of this job's average map output |
| */ |
| long getEstimatedMapOutputSize() { |
| long estimate = 0L; |
| if (job.desiredMaps() > 0) { |
| estimate = getEstimatedTotalMapOutputSize() / job.desiredMaps(); |
| } |
| return estimate; |
| } |
| |
| /** |
| * |
| * @return estimated length of this job's average reduce input |
| */ |
| long getEstimatedReduceInputSize() { |
| if(job.desiredReduces() == 0) {//no reduce output, so no size |
| return 0; |
| } else { |
| return getEstimatedTotalMapOutputSize() / job.desiredReduces(); |
| //estimate that each reduce gets an equal share of total map output |
| } |
| } |
| |
| /** |
| * the number of maps after which reduce starts launching |
| * @param numMaps the number of maps after which reduce starts |
| * launching. It acts as the upper bound for the threshhold, so |
| * that we can get right estimates before we reach these number |
| * of maps. |
| */ |
| void setThreshhold(int numMaps) { |
| threshholdToUse = Math.min(threshholdToUse, numMaps); |
| } |
| } |