MapSideDiskSpill.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.vaidya.postexdiagnosis.tests;
- import org.apache.hadoop.vaidya.statistics.job.JobStatistics;
- import org.apache.hadoop.vaidya.statistics.job.JobStatisticsInterface.JobKeys;
- import org.apache.hadoop.vaidya.statistics.job.JobStatisticsInterface.KeyDataType;
- import org.apache.hadoop.vaidya.statistics.job.JobStatisticsInterface.MapTaskKeys;
- import org.apache.hadoop.vaidya.statistics.job.JobStatisticsInterface.ReduceTaskKeys;
- import org.apache.hadoop.vaidya.statistics.job.MapTaskStatistics;
- import org.apache.hadoop.vaidya.DiagnosticTest;
- import org.w3c.dom.Element;
- import java.util.Hashtable;
- import java.util.List;
- /**
- *
- */
- public class MapSideDiskSpill extends DiagnosticTest {
- private double _impact;
- private JobStatistics _job;
- private long _numLocalBytesWrittenByMaps;
-
- /**
- *
- */
- public MapSideDiskSpill() {
- }
- /*
- *
- */
- @Override
- public double evaluate(JobStatistics job) {
-
- /*
- * Set the this._job
- */
- this._job = job;
-
- /*
- * Read the Normalization Factor
- */
- double normF = getInputElementDoubleValue("NormalizationFactor", 3.0);
-
- /*
- * Get the sorted reduce task list by number MapTaskKeys.OUTPUT_BYTES
- */
- List<MapTaskStatistics> srTaskList = job.getMapTaskList(MapTaskKeys.LOCAL_BYTES_WRITTEN, KeyDataType.LONG);
- int size = srTaskList.size();
- long numLocalBytesWrittenByMaps = 0;
- for (int i=0; i<size; i++) {
- numLocalBytesWrittenByMaps += srTaskList.get(i).getLongValue(MapTaskKeys.LOCAL_BYTES_WRITTEN);
- }
- this._numLocalBytesWrittenByMaps = numLocalBytesWrittenByMaps;
-
- /*
- * Map only job vs. map reduce job
- */
- if (job.getLongValue(JobKeys.TOTAL_REDUCES) > 0) {
- this._impact = (this._numLocalBytesWrittenByMaps - job.getLongValue(JobKeys.MAP_OUTPUT_BYTES))/job.getLongValue(JobKeys.MAP_OUTPUT_BYTES);
- } else {
- this._impact = this._numLocalBytesWrittenByMaps/job.getLongValue(JobKeys.MAP_OUTPUT_BYTES);
- }
-
- if (this._impact > normF) {
- this._impact = 1.0;
- } else {
- this._impact = this._impact/normF;
- }
-
- return this._impact;
-
- }
-
- /* (non-Javadoc)
- * @see org.apache.hadoop.contrib.utils.perfadvisor.diagnostic_rules.DiagnosticRule#getAdvice()
- */
- @Override
- public String getPrescription() {
- return
- "* Use combiner to lower the map output size.n" +
- "* Increase map side sort buffer size (io.sort.mb:"+this._job.getJobConf().getInt("io.sort.mb", 0) + ").n" +
- "* Increase index buffer size (io.sort.record.percent:"+ this._job.getJobConf().getInt("io.sort.record.percent", 0) + ") if number of Map Output Records are large. n" +
- "* Increase (io.sort.spill.percent:"+ this._job.getJobConf().getInt("io.sort.spill.percent", 0) + "), default 0.80 i.e. 80% of sort buffer size & index buffer size. n";
- }
- /* (non-Javadoc)
- * @see org.apache.hadoop.contrib.utils.perfadvisor.diagnostic_rules.DiagnosticRule#getReferenceDetails()
- */
- @Override
- public String getReferenceDetails() {
- String ref =
- "* TotalMapOutputBytes: "+this._job.getLongValue(JobKeys.MAP_OUTPUT_BYTES)+"n"+
- "* Total Local Bytes Written by Maps: "+this._numLocalBytesWrittenByMaps+"n"+
- "* Impact: "+ truncate(this._impact);
- return ref;
- }
- }