Java tutorial
/** * (C) Copyright IBM Corp. 2010, 2015 * * Licensed 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 com.ibm.bi.dml.runtime.matrix; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.mapred.JobClient; import org.apache.hadoop.mapred.JobConf; import org.apache.hadoop.mapred.RunningJob; import org.apache.hadoop.mapred.Counters.Group; import com.ibm.bi.dml.runtime.instructions.MRJobInstruction; import com.ibm.bi.dml.runtime.matrix.data.InputInfo; import com.ibm.bi.dml.runtime.matrix.data.OutputInfo; import com.ibm.bi.dml.runtime.matrix.data.TaggedInt; import com.ibm.bi.dml.runtime.matrix.data.WeightedCell; import com.ibm.bi.dml.runtime.matrix.mapred.GroupedAggMRCombiner; import com.ibm.bi.dml.runtime.matrix.mapred.GroupedAggMRMapper; import com.ibm.bi.dml.runtime.matrix.mapred.GroupedAggMRReducer; import com.ibm.bi.dml.runtime.matrix.mapred.MRJobConfiguration; import com.ibm.bi.dml.runtime.matrix.mapred.MRJobConfiguration.ConvertTarget; import com.ibm.bi.dml.runtime.util.MapReduceTool; public class GroupedAggMR { private static final Log LOG = LogFactory.getLog(GroupedAggMR.class.getName()); private GroupedAggMR() { //prevent instantiation via private constructor } public static JobReturn runJob(MRJobInstruction inst, String[] inputs, InputInfo[] inputInfos, long[] rlens, long[] clens, int[] brlens, int[] bclens, String grpAggInstructions, String simpleReduceInstructions/*only scalar or reorg instructions allowed*/, int numReducers, int replication, byte[] resultIndexes, String dimsUnknownFilePrefix, String[] outputs, OutputInfo[] outputInfos) throws Exception { JobConf job = new JobConf(GroupedAggMR.class); job.setJobName("GroupedAgg-MR"); //whether use block representation or cell representation //MRJobConfiguration.setMatrixValueClassForCM_N_COM(job, true); MRJobConfiguration.setMatrixValueClass(job, false); //added for handling recordreader instruction String[] realinputs = inputs; InputInfo[] realinputInfos = inputInfos; long[] realrlens = rlens; long[] realclens = clens; int[] realbrlens = brlens; int[] realbclens = bclens; byte[] realIndexes = new byte[inputs.length]; for (byte b = 0; b < realIndexes.length; b++) realIndexes[b] = b; //set up the input files and their format information MRJobConfiguration.setUpMultipleInputs(job, realIndexes, realinputs, realinputInfos, realbrlens, realbclens, true, ConvertTarget.WEIGHTEDCELL); //set up the dimensions of input matrices MRJobConfiguration.setMatricesDimensions(job, realIndexes, realrlens, realclens); MRJobConfiguration.setDimsUnknownFilePrefix(job, dimsUnknownFilePrefix); //set up the block size MRJobConfiguration.setBlocksSizes(job, realIndexes, realbrlens, realbclens); //set up the grouped aggregate instructions that will happen in the combiner and reducer MRJobConfiguration.setGroupedAggInstructions(job, grpAggInstructions); //set up the instructions that will happen in the reducer, after the aggregation instrucions MRJobConfiguration.setInstructionsInReducer(job, simpleReduceInstructions); //set up the number of reducers MRJobConfiguration.setNumReducers(job, numReducers, numReducers); //set up the replication factor for the results job.setInt("dfs.replication", replication); //set up what matrices are needed to pass from the mapper to reducer MRJobConfiguration.setUpOutputIndexesForMapper(job, realIndexes, null, null, grpAggInstructions, resultIndexes); MatrixCharacteristics[] stats = new MatrixCharacteristics[resultIndexes.length]; for (int i = 0; i < resultIndexes.length; i++) stats[i] = new MatrixCharacteristics(); // Print the complete instruction if (LOG.isTraceEnabled()) inst.printCompleteMRJobInstruction(stats); byte[] resultDimsUnknown = new byte[resultIndexes.length]; // Update resultDimsUnknown based on computed "stats" for (int i = 0; i < resultIndexes.length; i++) resultDimsUnknown[i] = (byte) 2; //set up the multiple output files, and their format information MRJobConfiguration.setUpMultipleOutputs(job, resultIndexes, resultDimsUnknown, outputs, outputInfos, false); // configure mapper and the mapper output key value pairs job.setMapperClass(GroupedAggMRMapper.class); job.setCombinerClass(GroupedAggMRCombiner.class); job.setMapOutputKeyClass(TaggedInt.class); job.setMapOutputValueClass(WeightedCell.class); //configure reducer job.setReducerClass(GroupedAggMRReducer.class); //set unique working dir MRJobConfiguration.setUniqueWorkingDir(job); //execute job RunningJob runjob = JobClient.runJob(job); //get important output statistics Group group = runjob.getCounters().getGroup(MRJobConfiguration.NUM_NONZERO_CELLS); for (int i = 0; i < resultIndexes.length; i++) { // number of non-zeros stats[i] = new MatrixCharacteristics(); stats[i].setNonZeros(group.getCounter(Integer.toString(i))); } String dir = dimsUnknownFilePrefix + "/" + runjob.getID().toString() + "_dimsFile"; stats = MapReduceTool.processDimsFiles(dir, stats); MapReduceTool.deleteFileIfExistOnHDFS(dir); return new JobReturn(stats, outputInfos, runjob.isSuccessful()); } }