org.smartfrog.services.hadoop.mapreduce.terasort.TeraValidateJob.java Source code

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Here is the source code for org.smartfrog.services.hadoop.mapreduce.terasort.TeraValidateJob.java

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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.smartfrog.services.hadoop.mapreduce.terasort;

import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.*;
import org.apache.hadoop.util.Tool;

import java.io.IOException;
import java.util.Iterator;

/**
 * Generate 1 mapper per a file that checks to make sure the keys are sorted within each file. The mapper also generates
 * "$file:begin", first key and "$file:end", last key. The reduce verifies that all of the start/end items are in order.
 * Any output from the reduce is problem report. <p> To run the program: <b>bin/hadoop jar hadoop-examples-*.jar
 * teravalidate out-dir report-dir</b> <p> If there is any output, something is wrong and the output of the reduce will
 * have the problem report.
 */
@SuppressWarnings({ "deprecation" })

public class TeraValidateJob extends Configured implements Tool {
    private static final Text error = new Text("error");

    static class ValidateMapper extends MapReduceBase implements Mapper<Text, Text, Text, Text> {
        private Text lastKey;
        private OutputCollector<Text, Text> output;
        private String filename;

        /**
         * Get the final part of the input name
         *
         * @param split the input split
         * @return the "part-00000" for the input
         */
        private String getFilename(FileSplit split) {
            return split.getPath().getName();
        }

        public void map(Text key, Text value, OutputCollector<Text, Text> output, Reporter reporter)
                throws IOException {
            if (lastKey == null) {
                filename = getFilename((FileSplit) reporter.getInputSplit());
                output.collect(new Text(filename + ":begin"), key);
                lastKey = new Text();
                this.output = output;
            } else {
                if (key.compareTo(lastKey) < 0) {
                    output.collect(error, new Text(
                            "misorder in " + filename + " last: '" + lastKey + "' current: '" + key + "'"));
                }
            }
            lastKey.set(key);
        }

        public void close() throws IOException {
            if (lastKey != null) {
                output.collect(new Text(filename + ":end"), lastKey);
            }
        }
    }

    /**
     * Check the boundaries between the output files by making sure that the boundary keys are always increasing. Also
     * passes any error reports along intact.
     */
    static class ValidateReducer extends MapReduceBase implements Reducer<Text, Text, Text, Text> {
        private boolean firstKey = true;
        private Text lastKey = new Text();
        private Text lastValue = new Text();

        public void reduce(Text key, Iterator<Text> values, OutputCollector<Text, Text> output, Reporter reporter)
                throws IOException {
            if (error.equals(key)) {
                while (values.hasNext()) {
                    output.collect(key, values.next());
                }
            } else {
                Text value = values.next();
                if (firstKey) {
                    firstKey = false;
                } else {
                    if (value.compareTo(lastValue) < 0) {
                        output.collect(error, new Text("misordered keys last: " + lastKey + " '" + lastValue
                                + "' current: " + key + " '" + value + "'"));
                    }
                }
                lastKey.set(key);
                lastValue.set(value);
            }
        }

    }

    public int run(String[] args) throws Exception {
        JobConf job = (JobConf) getConf();
        TeraInputFormat.setInputPaths(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));
        job.setJobName("TeraValidate");
        job.setJarByClass(TeraValidateJob.class);
        job.setMapperClass(ValidateMapper.class);
        job.setReducerClass(ValidateReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(Text.class);
        // force a single reducer
        job.setNumReduceTasks(1);
        // force a single split 
        job.setLong("mapred.min.split.size", Long.MAX_VALUE);
        job.setInputFormat(TeraInputFormat.class);
        JobClient.runJob(job);
        return 0;
    }

}