com.cloudera.recordservice.examples.mapreduce.MapReduceAgeCount.java Source code

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Here is the source code for com.cloudera.recordservice.examples.mapreduce.MapReduceAgeCount.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 com.cloudera.recordservice.examples.mapreduce;

import java.io.IOException;

import org.apache.avro.Schema;
import org.apache.avro.mapred.AvroKey;
import org.apache.avro.mapred.AvroValue;
import org.apache.avro.mapreduce.AvroJob;
import org.apache.avro.mapreduce.AvroKeyValueOutputFormat;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

import com.cloudera.recordservice.examples.UserKey;
import com.cloudera.recordservice.examples.UserValue;
import com.cloudera.recordservice.mr.RecordServiceConfig;

/**
 * Count the sum of age for users with same favorite_color.
 */
public class MapReduceAgeCount extends Configured implements Tool {

    public static class AgeCountMapper extends Mapper<AvroKey<UserKey>, AvroValue<UserValue>, Text, IntWritable> {
        private static final Text COLOR = new Text();
        private static final IntWritable AGE = new IntWritable();

        @Override
        public void map(AvroKey<UserKey> key, AvroValue<UserValue> value, Context context)
                throws IOException, InterruptedException {
            // The record with Null age is invalid and will not be counted.
            if (value.datum().getAge() != null) {
                AGE.set(value.datum().getAge());
                if (key.datum().getFavoriteColor() == null) {
                    COLOR.set("none");
                } else {
                    COLOR.set(key.datum().getFavoriteColor().toString());
                }
                context.write(COLOR, AGE);
            }
        }
    }

    public static class AgeCountReducer
            extends Reducer<Text, IntWritable, AvroKey<CharSequence>, AvroValue<Integer>> {
        private static final AvroKey<CharSequence> COLOR = new AvroKey<CharSequence>();
        private static final AvroValue<Integer> SUM_OF_AGE = new AvroValue<Integer>();

        @Override
        public void reduce(Text key, Iterable<IntWritable> values, Context context)
                throws IOException, InterruptedException {
            int sum = 0;
            for (IntWritable value : values) {
                sum += value.get();
            }
            COLOR.datum(key.toString());
            SUM_OF_AGE.datum(sum);
            context.write(COLOR, SUM_OF_AGE);
        }
    }

    public int run(String[] args) throws Exception {
        org.apache.log4j.BasicConfigurator.configure();

        if (args.length != 2) {
            System.err.println("Usage: MapReduceAgeCount <input path> <output path>");
            return -1;
        }

        Job job = Job.getInstance(getConf());
        job.setJarByClass(MapReduceAgeCount.class);
        job.setJobName("Age Count");

        // RECORDSERVICE:
        // To read from a table instead of a path, comment out
        // FileInputFormat.setInputPaths() and instead use:
        // FileInputFormat.setInputPaths(job, new Path(args[0]));
        RecordServiceConfig.setInputTable(job.getConfiguration(), null, args[0]);

        // RECORDSERVICE:
        // Use the RecordService version of the AvroKeyValueInputFormat
        job.setInputFormatClass(com.cloudera.recordservice.avro.mapreduce.AvroKeyValueInputFormat.class);
        FileOutputFormat.setOutputPath(job, new Path(args[1]));

        job.setMapperClass(AgeCountMapper.class);
        // Set schema for input key and value.
        AvroJob.setInputKeySchema(job, UserKey.getClassSchema());
        AvroJob.setInputValueSchema(job, UserValue.getClassSchema());

        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(IntWritable.class);

        job.setOutputFormatClass(AvroKeyValueOutputFormat.class);
        job.setReducerClass(AgeCountReducer.class);
        AvroJob.setOutputKeySchema(job, Schema.create(Schema.Type.STRING));
        AvroJob.setOutputValueSchema(job, Schema.create(Schema.Type.INT));

        return (job.waitForCompletion(true) ? 0 : 1);
    }

    public static void main(String[] args) throws Exception {
        int res = ToolRunner.run(new MapReduceAgeCount(), args);
        System.exit(res);
    }
}