/**
* 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.mahout.math.hadoop.stochasticsvd;
import java.io.Closeable;
import java.io.IOException;
import java.util.Deque;
import com.google.common.collect.Lists;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.SequenceFile.CompressionType;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.compress.DefaultCodec;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.lib.MultipleOutputs;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
import org.apache.mahout.common.IOUtils;
import org.apache.mahout.math.DenseVector;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.VectorWritable;
import org.apache.mahout.math.function.Functions;
import org.apache.mahout.math.hadoop.stochasticsvd.qr.QRFirstStep;
/**
* Compute first level of QHat-transpose blocks.
* <P>
*
* See Mahout-376 working notes for details.
* <P>
*
* Uses some of Hadoop deprecated api wherever newer api is not available.
* Hence, @SuppressWarnings("deprecation") for imports (MAHOUT-593).
* <P>
*
*/
@SuppressWarnings("deprecation")
public final class QJob {
public static final String PROP_OMEGA_SEED = "ssvd.omegaseed";
public static final String PROP_K = QRFirstStep.PROP_K;
public static final String PROP_P = QRFirstStep.PROP_P;
public static final String PROP_SB_PATH = "ssvdpca.sb.path";
public static final String PROP_AROWBLOCK_SIZE =
QRFirstStep.PROP_AROWBLOCK_SIZE;
public static final String OUTPUT_RHAT = "R";
public static final String OUTPUT_QHAT = "QHat";
private QJob() {
}
public static class QMapper
extends
Mapper<Writable, VectorWritable, SplitPartitionedWritable, VectorWritable> {
private MultipleOutputs outputs;
private final Deque<Closeable> closeables = Lists.newLinkedList();
private SplitPartitionedWritable qHatKey;
private SplitPartitionedWritable rHatKey;
private Vector yRow;
private Vector sb;
private Omega omega;
private int kp;
private QRFirstStep qr;
@Override
protected void setup(Context context) throws IOException,
InterruptedException {
Configuration conf = context.getConfiguration();
int k = Integer.parseInt(conf.get(PROP_K));
int p = Integer.parseInt(conf.get(PROP_P));
kp = k + p;
long omegaSeed = Long.parseLong(conf.get(PROP_OMEGA_SEED));
omega = new Omega(omegaSeed, k + p);
String sbPathStr = conf.get(PROP_SB_PATH);
if (sbPathStr != null) {
sb = SSVDHelper.loadAndSumUpVectors(new Path(sbPathStr), conf);
}
outputs = new MultipleOutputs(new JobConf(conf));
closeables.addFirst(new Closeable() {
@Override
public void close() throws IOException {
outputs.close();
}
});
qHatKey = new SplitPartitionedWritable(context);
rHatKey = new SplitPartitionedWritable(context);
OutputCollector<Writable, DenseBlockWritable> qhatCollector =
new OutputCollector<Writable, DenseBlockWritable>() {
@Override
@SuppressWarnings("unchecked")
public void collect(Writable nil, DenseBlockWritable dbw)
throws IOException {
outputs.getCollector(OUTPUT_QHAT, null).collect(qHatKey, dbw);
qHatKey.incrementItemOrdinal();
}
};
OutputCollector<Writable, VectorWritable> rhatCollector =
new OutputCollector<Writable, VectorWritable>() {
@Override
@SuppressWarnings("unchecked")
public void collect(Writable nil, VectorWritable rhat)
throws IOException {
outputs.getCollector(OUTPUT_RHAT, null).collect(rHatKey, rhat);
rHatKey.incrementItemOrdinal();
}
};
qr = new QRFirstStep(conf, qhatCollector, rhatCollector);
closeables.addFirst(qr); // important: qr closes first!!
yRow = new DenseVector(kp);
}
@Override
protected void map(Writable key, VectorWritable value, Context context)
throws IOException, InterruptedException {
omega.computeYRow(value.get(), yRow);
if (sb != null) {
yRow.assign(sb, Functions.MINUS);
}
qr.collect(key, yRow);
}
@Override
protected void cleanup(Context context) throws IOException,
InterruptedException {
IOUtils.close(closeables);
}
}
public static void run(Configuration conf,
Path[] inputPaths,
Path sbPath,
Path outputPath,
int aBlockRows,
int minSplitSize,
int k,
int p,
long seed,
int numReduceTasks) throws ClassNotFoundException,
InterruptedException, IOException {
JobConf oldApiJob = new JobConf(conf);
MultipleOutputs.addNamedOutput(oldApiJob,
OUTPUT_QHAT,
org.apache.hadoop.mapred.SequenceFileOutputFormat.class,
SplitPartitionedWritable.class,
DenseBlockWritable.class);
MultipleOutputs.addNamedOutput(oldApiJob,
OUTPUT_RHAT,
org.apache.hadoop.mapred.SequenceFileOutputFormat.class,
SplitPartitionedWritable.class,
VectorWritable.class);
Job job = new Job(oldApiJob);
job.setJobName("Q-job");
job.setJarByClass(QJob.class);
job.setInputFormatClass(SequenceFileInputFormat.class);
FileInputFormat.setInputPaths(job, inputPaths);
if (minSplitSize > 0) {
FileInputFormat.setMinInputSplitSize(job, minSplitSize);
}
FileOutputFormat.setOutputPath(job, outputPath);
FileOutputFormat.setCompressOutput(job, true);
FileOutputFormat.setOutputCompressorClass(job, DefaultCodec.class);
SequenceFileOutputFormat.setOutputCompressionType(job,
CompressionType.BLOCK);
job.setMapOutputKeyClass(SplitPartitionedWritable.class);
job.setMapOutputValueClass(VectorWritable.class);
job.setOutputKeyClass(SplitPartitionedWritable.class);
job.setOutputValueClass(VectorWritable.class);
job.setMapperClass(QMapper.class);
job.getConfiguration().setInt(PROP_AROWBLOCK_SIZE, aBlockRows);
job.getConfiguration().setLong(PROP_OMEGA_SEED, seed);
job.getConfiguration().setInt(PROP_K, k);
job.getConfiguration().setInt(PROP_P, p);
if (sbPath != null) {
job.getConfiguration().set(PROP_SB_PATH, sbPath.toString());
}
/*
* number of reduce tasks doesn't matter. we don't actually send anything to
* reducers.
*/
job.setNumReduceTasks(0 /* numReduceTasks */);
job.submit();
job.waitForCompletion(false);
if (!job.isSuccessful()) {
throw new IOException("Q job unsuccessful.");
}
}
}