Created
March 3, 2014 12:55
-
-
Save rishav-rohit/9324374 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
package com.rishav.avro.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.AvroKeyInputFormat; | |
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.NullWritable; | |
import org.apache.hadoop.mapreduce.Job; | |
import org.apache.hadoop.mapreduce.Mapper; | |
import org.apache.hadoop.mapreduce.Reducer; | |
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; | |
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; | |
import org.apache.hadoop.util.GenericOptionsParser; | |
import org.apache.hadoop.util.Tool; | |
import org.apache.hadoop.util.ToolRunner; | |
import com.rishav.avro.IntPair; | |
import com.rishav.avro.student_marks; | |
public class AvroAverageDriver extends Configured implements Tool{ | |
public static class AvroAverageMapper extends | |
Mapper<AvroKey<student_marks>, NullWritable, IntWritable, IntPair> { | |
protected void map(AvroKey<student_marks> key, NullWritable value, Context context) | |
throws IOException, InterruptedException { | |
IntWritable s_id = new IntWritable(key.datum().getStudentId()); | |
IntPair marks_one = new IntPair(key.datum().getMarks(), 1); | |
context.write(s_id, marks_one); | |
} | |
} // end of mapper class | |
public static class AvroAverageCombiner extends | |
Reducer<IntWritable, IntPair, IntWritable, IntPair> { | |
IntPair p_sum_count = new IntPair(); | |
Integer p_sum = new Integer(0); | |
Integer p_count = new Integer(0); | |
protected void reduce(IntWritable key, Iterable<IntPair> values, Context context) | |
throws IOException, InterruptedException { | |
p_sum = 0; | |
p_count = 0; | |
for (IntPair value : values) { | |
p_sum += value.getFirstInt(); | |
p_count += value.getSecondInt(); | |
} | |
p_sum_count.set(p_sum, p_count); | |
context.write(key, p_sum_count); | |
} | |
} // end of combiner class | |
public static class AvroAverageReducer extends | |
Reducer<IntWritable, IntPair, AvroKey<Integer>, AvroValue<Float>> { | |
Integer f_sum = 0; | |
Integer f_count = 0; | |
protected void reduce(IntWritable key, Iterable<IntPair> values, Context context) | |
throws IOException, InterruptedException { | |
f_sum = 0; | |
f_count = 0; | |
for (IntPair value : values) { | |
f_sum += value.getFirstInt(); | |
f_count += value.getSecondInt(); | |
} | |
Float average = (float)f_sum/f_count; | |
Integer s_id = new Integer(key.toString()); | |
context.write(new AvroKey<Integer>(s_id), new AvroValue<Float>(average)); | |
} | |
} // end of reducer class | |
@Override | |
public int run(String[] rawArgs) throws Exception { | |
if (rawArgs.length != 2) { | |
System.err.printf("Usage: %s [generic options] <input> <output>\n", | |
getClass().getName()); | |
ToolRunner.printGenericCommandUsage(System.err); | |
return -1; | |
} | |
Job job = new Job(super.getConf()); | |
job.setJarByClass(AvroAverageDriver.class); | |
job.setJobName("Avro Average"); | |
String[] args = new GenericOptionsParser(rawArgs).getRemainingArgs(); | |
Path inPath = new Path(args[0]); | |
Path outPath = new Path(args[1]); | |
FileInputFormat.setInputPaths(job, inPath); | |
FileOutputFormat.setOutputPath(job, outPath); | |
outPath.getFileSystem(super.getConf()).delete(outPath, true); | |
job.setInputFormatClass(AvroKeyInputFormat.class); | |
job.setMapperClass(AvroAverageMapper.class); | |
AvroJob.setInputKeySchema(job, student_marks.getClassSchema()); | |
job.setMapOutputKeyClass(IntWritable.class); | |
job.setMapOutputValueClass(IntPair.class); | |
job.setCombinerClass(AvroAverageCombiner.class); | |
job.setOutputFormatClass(AvroKeyValueOutputFormat.class); | |
job.setReducerClass(AvroAverageReducer.class); | |
AvroJob.setOutputKeySchema(job, Schema.create(Schema.Type.INT)); | |
AvroJob.setOutputValueSchema(job, Schema.create(Schema.Type.FLOAT)); | |
return (job.waitForCompletion(true) ? 0 : 1); | |
} | |
public static void main(String[] args) throws Exception { | |
int result = ToolRunner.run(new AvroAverageDriver(), args); | |
System.exit(result); | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment