/**
* 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.hcatalog.utils;
import java.io.IOException;
import java.util.Iterator;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.util.GenericOptionsParser;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.hcatalog.common.HCatConstants;
import org.apache.hcatalog.data.DefaultHCatRecord;
import org.apache.hcatalog.data.HCatRecord;
import org.apache.hcatalog.data.schema.HCatSchema;
import org.apache.hcatalog.mapreduce.HCatInputFormat;
import org.apache.hcatalog.mapreduce.HCatOutputFormat;
import org.apache.hcatalog.mapreduce.InputJobInfo;
import org.apache.hcatalog.mapreduce.OutputJobInfo;
/**
* This is a map reduce test for testing hcat which goes against the "numbers"
* table. It performs a group by on the first column and a SUM operation on the
* other columns. This is to simulate a typical operation in a map reduce
* program to test that hcat hands the right data to the map reduce program
*
* Usage: hadoop jar sumnumbers <serveruri> <output dir> <-libjars hive-hcat
* jar> The <tab|ctrla> argument controls the output delimiter The hcat jar
* location should be specified as file://<full path to jar>
*/
public class GroupByAge extends Configured implements Tool {
public static class Map extends
Mapper<WritableComparable, HCatRecord, IntWritable, IntWritable> {
int age;
@Override
protected void map(
WritableComparable key,
HCatRecord value,
org.apache.hadoop.mapreduce.Mapper<WritableComparable, HCatRecord, IntWritable, IntWritable>.Context context)
throws IOException, InterruptedException {
age = (Integer) value.get(1);
context.write(new IntWritable(age), new IntWritable(1));
}
}
public static class Reduce extends Reducer<IntWritable, IntWritable,
WritableComparable, HCatRecord> {
@Override
protected void reduce(IntWritable key, java.lang.Iterable<IntWritable>
values, org.apache.hadoop.mapreduce.Reducer<IntWritable,IntWritable,WritableComparable,HCatRecord>.Context context)
throws IOException ,InterruptedException {
int sum = 0;
Iterator<IntWritable> iter = values.iterator();
while (iter.hasNext()) {
sum++;
iter.next();
}
HCatRecord record = new DefaultHCatRecord(2);
record.set(0, key.get());
record.set(1, sum);
context.write(null, record);
}
}
public int run(String[] args) throws Exception {
Configuration conf = getConf();
args = new GenericOptionsParser(conf, args).getRemainingArgs();
String serverUri = args[0];
String inputTableName = args[1];
String outputTableName = args[2];
String dbName = null;
String principalID = System
.getProperty(HCatConstants.HCAT_METASTORE_PRINCIPAL);
if (principalID != null)
conf.set(HCatConstants.HCAT_METASTORE_PRINCIPAL, principalID);
Job job = new Job(conf, "GroupByAge");
HCatInputFormat.setInput(job, InputJobInfo.create(dbName,
inputTableName, null));
// initialize HCatOutputFormat
job.setInputFormatClass(HCatInputFormat.class);
job.setJarByClass(GroupByAge.class);
job.setMapperClass(Map.class);
job.setReducerClass(Reduce.class);
job.setMapOutputKeyClass(IntWritable.class);
job.setMapOutputValueClass(IntWritable.class);
job.setOutputKeyClass(WritableComparable.class);
job.setOutputValueClass(DefaultHCatRecord.class);
HCatOutputFormat.setOutput(job, OutputJobInfo.create(dbName,
outputTableName, null));
HCatSchema s = HCatOutputFormat.getTableSchema(job);
System.err.println("INFO: output schema explicitly set for writing:"
+ s);
HCatOutputFormat.setSchema(job, s);
job.setOutputFormatClass(HCatOutputFormat.class);
return (job.waitForCompletion(true) ? 0 : 1);
}
public static void main(String[] args) throws Exception {
int exitCode = ToolRunner.run(new GroupByAge(), args);
System.exit(exitCode);
}
}