MapReduce编程系列 — 3：数据去重
1、项目名称：
2、程序代码：
package com.dedup; import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
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.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser; public class Dedup {
//map将输入中的value复制到输出数据的key上，并直接输出，注意参数类型和个数
public static class Map extends Mapper<Object, Text, Text, Text>{
public static Text line = new Text();
//注意参数类型和个数
public void map(Object key , Text value , Context context) throws IOException,InterruptedException{
System.out.println("mapper.......");
System.out.println("key:"+key+" value:"+value);
line = value;
context.write(line, new Text(" "));
System.out.println("line:"+ line +" value"+ value +" context:" + context);
}
}
//reduce将输入中的key复制到输出数据的key上，并直接输出，注意参数类型和个数
public static class Reduce extends Reducer<Text, Text, Text, Text>{
//注意参数类型和个数
public void reduce(Text key , Iterable<Text> values, Context context)throws IOException,InterruptedException{
System.out.println("reducer.......");
System.out.println("key:"+key+" values:"+values);
context.write(key, new Text(" "));
System.out.println("key:"+key+" values"+values+" context:"+context);
}
} public static void main(String [] args)throws Exception{
Configuration conf = new Configuration();
String otherArgs[] = new GenericOptionsParser(conf,args).getRemainingArgs();
if(otherArgs.length!=2){
System.out.println("Usage:dedup <in> <out>");
System.exit(2);
}
Job job = new Job(conf,"Data Deduplication");
job.setJarByClass(Dedup.class); job.setMapperClass(Map.class);
job.setReducerClass(Reduce.class); job.setOutputKeyClass(Text.class);
job.setOutputValueClass(Text.class); FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));
System.exit(job.waitForCompletion(true)? 0 : 1 );
}
}
3、测试数据：
file1：
2006-6-9 a
2006-6-10 b
2006-6-11 c
2006-6-12 d
2006-6-13 a
2006-6-14 b
2006-6-15 c
2006-6-11 c
2006-6-10 b
2006-6-11 c
2006-6-12 d
2006-6-13 a
2006-6-14 b
2006-6-15 c
2006-6-11 c
file2：
2006-6-9 b
2006-6-10 a
2006-6-11 b
2006-6-12 d
2006-6-13 a
2006-6-14 c
2006-6-15 d
2006-6-11 c
2006-6-10 a
2006-6-11 b
2006-6-12 d
2006-6-13 a
2006-6-14 c
2006-6-15 d
2006-6-11 c
4、运行过程：
14/09/21 16:51:16 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
14/09/21 16:51:16 WARN mapred.JobClient: No job jar file set. User classes may not be found. See JobConf(Class) or JobConf#setJar(String).
14/09/21 16:51:16 INFO input.FileInputFormat: Total input paths to process : 2
14/09/21 16:51:16 WARN snappy.LoadSnappy: Snappy native library not loaded
14/09/21 16:51:16 INFO mapred.JobClient: Running job: job_local_0001
14/09/21 16:51:16 INFO util.ProcessTree: setsid exited with exit code 0
14/09/21 16:51:16 INFO mapred.Task: Using ResourceCalculatorPlugin : org.apache.hadoop.util.LinuxResourceCalculatorPlugin@2e9aa770
14/09/21 16:51:16 INFO mapred.MapTask: io.sort.mb = 100
14/09/21 16:51:16 INFO mapred.MapTask: data buffer = 79691776/99614720
14/09/21 16:51:16 INFO mapred.MapTask: record buffer = 262144/327680
mapper.......
key:0 value:2006-6-9 a
line:2006-6-9 a value2006-6-9 a context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:11 value:2006-6-10 b
line:2006-6-10 b value2006-6-10 b context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:23 value:2006-6-11 c
line:2006-6-11 c value2006-6-11 c context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:35 value:2006-6-12 d
line:2006-6-12 d value2006-6-12 d context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:47 value:2006-6-13 a
line:2006-6-13 a value2006-6-13 a context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:59 value:2006-6-14 b
line:2006-6-14 b value2006-6-14 b context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:71 value:2006-6-15 c
line:2006-6-15 c value2006-6-15 c context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:83 value:2006-6-11 c
line:2006-6-11 c value2006-6-11 c context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
14/09/21 16:51:16 INFO mapred.MapTask: Starting flush of map output
14/09/21 16:51:16 INFO mapred.MapTask: Finished spill 0
14/09/21 16:51:16 INFO mapred.Task: Task:attempt_local_0001_m_000000_0 is done. And is in the process of commiting
14/09/21 16:51:17 INFO mapred.JobClient: map 0% reduce 0%
14/09/21 16:51:19 INFO mapred.LocalJobRunner:
14/09/21 16:51:19 INFO mapred.Task: Task 'attempt_local_0001_m_000000_0' done.
14/09/21 16:51:19 INFO mapred.Task: Using ResourceCalculatorPlugin : org.apache.hadoop.util.LinuxResourceCalculatorPlugin@3697e580
14/09/21 16:51:19 INFO mapred.MapTask: io.sort.mb = 100
14/09/21 16:51:19 INFO mapred.MapTask: data buffer = 79691776/99614720
14/09/21 16:51:19 INFO mapred.MapTask: record buffer = 262144/327680
mapper.......
key:0 value:2006-6-9 b
line:2006-6-9 b value2006-6-9 b context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:11 value:2006-6-10 a
line:2006-6-10 a value2006-6-10 a context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:23 value:2006-6-11 b
line:2006-6-11 b value2006-6-11 b context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:35 value:2006-6-12 d
line:2006-6-12 d value2006-6-12 d context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:47 value:2006-6-13 a
line:2006-6-13 a value2006-6-13 a context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:59 value:2006-6-14 c
line:2006-6-14 c value2006-6-14 c context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:71 value:2006-6-15 d
line:2006-6-15 d value2006-6-15 d context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:83 value:2006-6-11 c
line:2006-6-11 c value2006-6-11 c context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
14/09/21 16:51:19 INFO mapred.MapTask: Starting flush of map output
14/09/21 16:51:19 INFO mapred.MapTask: Finished spill 0
14/09/21 16:51:19 INFO mapred.Task: Task:attempt_local_0001_m_000001_0 is done. And is in the process of commiting
14/09/21 16:51:20 INFO mapred.JobClient: map 100% reduce 0%
14/09/21 16:51:22 INFO mapred.LocalJobRunner:
14/09/21 16:51:22 INFO mapred.Task: Task 'attempt_local_0001_m_000001_0' done.
14/09/21 16:51:22 INFO mapred.Task: Using ResourceCalculatorPlugin : org.apache.hadoop.util.LinuxResourceCalculatorPlugin@3c844c07
14/09/21 16:51:22 INFO mapred.LocalJobRunner:
14/09/21 16:51:22 INFO mapred.Merger: Merging 2 sorted segments
14/09/21 16:51:22 INFO mapred.Merger: Down to the last merge-pass, with 2 segments left of total size: 258 bytes
14/09/21 16:51:22 INFO mapred.LocalJobRunner:
reducer.......
key:2006-6-10 a values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-10 a valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-10 b values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-10 b valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-11 b values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-11 b valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-11 c values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-11 c valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-12 d values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-12 d valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-13 a values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-13 a valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-14 b values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-14 b valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-14 c values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-14 c valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-15 c values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-15 c valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-15 d values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-15 d valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-9 a values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-9 a valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-9 b values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-9 b valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
14/09/21 16:51:22 INFO mapred.Task: Task:attempt_local_0001_r_000000_0 is done. And is in the process of commiting
14/09/21 16:51:22 INFO mapred.LocalJobRunner:
14/09/21 16:51:22 INFO mapred.Task: Task attempt_local_0001_r_000000_0 is allowed to commit now
14/09/21 16:51:22 INFO output.FileOutputCommitter: Saved output of task 'attempt_local_0001_r_000000_0' to hdfs://localhost:9000/user/hadoop/dedup_output
14/09/21 16:51:25 INFO mapred.LocalJobRunner: reduce > reduce
14/09/21 16:51:25 INFO mapred.Task: Task 'attempt_local_0001_r_000000_0' done.
14/09/21 16:51:26 INFO mapred.JobClient: map 100% reduce 100%
14/09/21 16:51:26 INFO mapred.JobClient: Job complete: job_local_0001
14/09/21 16:51:26 INFO mapred.JobClient: Counters: 22
14/09/21 16:51:26 INFO mapred.JobClient: Map-Reduce Framework
14/09/21 16:51:26 INFO mapred.JobClient: Spilled Records=32
14/09/21 16:51:26 INFO mapred.JobClient: Map output materialized bytes=266
14/09/21 16:51:26 INFO mapred.JobClient: Reduce input records=16
14/09/21 16:51:26 INFO mapred.JobClient: Virtual memory (bytes) snapshot=0
14/09/21 16:51:26 INFO mapred.JobClient: Map input records=16
14/09/21 16:51:26 INFO mapred.JobClient: SPLIT_RAW_BYTES=232
14/09/21 16:51:26 INFO mapred.JobClient: Map output bytes=222
14/09/21 16:51:26 INFO mapred.JobClient: Reduce shuffle bytes=0
14/09/21 16:51:26 INFO mapred.JobClient: Physical memory (bytes) snapshot=0
14/09/21 16:51:26 INFO mapred.JobClient: Reduce input groups=12
14/09/21 16:51:26 INFO mapred.JobClient: Combine output records=0
14/09/21 16:51:26 INFO mapred.JobClient: Reduce output records=12
14/09/21 16:51:26 INFO mapred.JobClient: Map output records=16
14/09/21 16:51:26 INFO mapred.JobClient: Combine input records=0
14/09/21 16:51:26 INFO mapred.JobClient: CPU time spent (ms)=0
14/09/21 16:51:26 INFO mapred.JobClient: Total committed heap usage (bytes)=813170688
14/09/21 16:51:26 INFO mapred.JobClient: File Input Format Counters
14/09/21 16:51:26 INFO mapred.JobClient: Bytes Read=190
14/09/21 16:51:26 INFO mapred.JobClient: FileSystemCounters
14/09/21 16:51:26 INFO mapred.JobClient: HDFS_BYTES_READ=475
14/09/21 16:51:26 INFO mapred.JobClient: FILE_BYTES_WRITTEN=122061
14/09/21 16:51:26 INFO mapred.JobClient: FILE_BYTES_READ=1665
14/09/21 16:51:26 INFO mapred.JobClient: HDFS_BYTES_WRITTEN=166
14/09/21 16:51:26 INFO mapred.JobClient: File Output Format Counters
14/09/21 16:51:26 INFO mapred.JobClient: Bytes Written=166
14/09/21 16:51:16 WARN mapred.JobClient: No job jar file set. User classes may not be found. See JobConf(Class) or JobConf#setJar(String).
14/09/21 16:51:16 INFO input.FileInputFormat: Total input paths to process : 2
14/09/21 16:51:16 WARN snappy.LoadSnappy: Snappy native library not loaded
14/09/21 16:51:16 INFO mapred.JobClient: Running job: job_local_0001
14/09/21 16:51:16 INFO util.ProcessTree: setsid exited with exit code 0
14/09/21 16:51:16 INFO mapred.Task: Using ResourceCalculatorPlugin : org.apache.hadoop.util.LinuxResourceCalculatorPlugin@2e9aa770
14/09/21 16:51:16 INFO mapred.MapTask: io.sort.mb = 100
14/09/21 16:51:16 INFO mapred.MapTask: data buffer = 79691776/99614720
14/09/21 16:51:16 INFO mapred.MapTask: record buffer = 262144/327680
mapper.......
key:0 value:2006-6-9 a
line:2006-6-9 a value2006-6-9 a context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:11 value:2006-6-10 b
line:2006-6-10 b value2006-6-10 b context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:23 value:2006-6-11 c
line:2006-6-11 c value2006-6-11 c context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:35 value:2006-6-12 d
line:2006-6-12 d value2006-6-12 d context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:47 value:2006-6-13 a
line:2006-6-13 a value2006-6-13 a context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:59 value:2006-6-14 b
line:2006-6-14 b value2006-6-14 b context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:71 value:2006-6-15 c
line:2006-6-15 c value2006-6-15 c context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
mapper.......
key:83 value:2006-6-11 c
line:2006-6-11 c value2006-6-11 c context:org.apache.hadoop.mapreduce.Mapper$Context@2d3b0087
14/09/21 16:51:16 INFO mapred.MapTask: Starting flush of map output
14/09/21 16:51:16 INFO mapred.MapTask: Finished spill 0
14/09/21 16:51:16 INFO mapred.Task: Task:attempt_local_0001_m_000000_0 is done. And is in the process of commiting
14/09/21 16:51:17 INFO mapred.JobClient: map 0% reduce 0%
14/09/21 16:51:19 INFO mapred.LocalJobRunner:
14/09/21 16:51:19 INFO mapred.Task: Task 'attempt_local_0001_m_000000_0' done.
14/09/21 16:51:19 INFO mapred.Task: Using ResourceCalculatorPlugin : org.apache.hadoop.util.LinuxResourceCalculatorPlugin@3697e580
14/09/21 16:51:19 INFO mapred.MapTask: io.sort.mb = 100
14/09/21 16:51:19 INFO mapred.MapTask: data buffer = 79691776/99614720
14/09/21 16:51:19 INFO mapred.MapTask: record buffer = 262144/327680
mapper.......
key:0 value:2006-6-9 b
line:2006-6-9 b value2006-6-9 b context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:11 value:2006-6-10 a
line:2006-6-10 a value2006-6-10 a context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:23 value:2006-6-11 b
line:2006-6-11 b value2006-6-11 b context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:35 value:2006-6-12 d
line:2006-6-12 d value2006-6-12 d context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:47 value:2006-6-13 a
line:2006-6-13 a value2006-6-13 a context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:59 value:2006-6-14 c
line:2006-6-14 c value2006-6-14 c context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:71 value:2006-6-15 d
line:2006-6-15 d value2006-6-15 d context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
mapper.......
key:83 value:2006-6-11 c
line:2006-6-11 c value2006-6-11 c context:org.apache.hadoop.mapreduce.Mapper$Context@319af5dd
14/09/21 16:51:19 INFO mapred.MapTask: Starting flush of map output
14/09/21 16:51:19 INFO mapred.MapTask: Finished spill 0
14/09/21 16:51:19 INFO mapred.Task: Task:attempt_local_0001_m_000001_0 is done. And is in the process of commiting
14/09/21 16:51:20 INFO mapred.JobClient: map 100% reduce 0%
14/09/21 16:51:22 INFO mapred.LocalJobRunner:
14/09/21 16:51:22 INFO mapred.Task: Task 'attempt_local_0001_m_000001_0' done.
14/09/21 16:51:22 INFO mapred.Task: Using ResourceCalculatorPlugin : org.apache.hadoop.util.LinuxResourceCalculatorPlugin@3c844c07
14/09/21 16:51:22 INFO mapred.LocalJobRunner:
14/09/21 16:51:22 INFO mapred.Merger: Merging 2 sorted segments
14/09/21 16:51:22 INFO mapred.Merger: Down to the last merge-pass, with 2 segments left of total size: 258 bytes
14/09/21 16:51:22 INFO mapred.LocalJobRunner:
reducer.......
key:2006-6-10 a values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-10 a valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-10 b values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-10 b valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-11 b values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-11 b valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-11 c values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-11 c valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-12 d values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-12 d valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-13 a values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-13 a valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-14 b values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-14 b valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-14 c values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-14 c valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-15 c values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-15 c valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-15 d values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-15 d valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-9 a values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-9 a valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
reducer.......
key:2006-6-9 b values:org.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78
key:2006-6-9 b valuesorg.apache.hadoop.mapreduce.ReduceContext$ValueIterable@9c8fd78 context:org.apache.hadoop.mapreduce.Reducer$Context@52767ce8
14/09/21 16:51:22 INFO mapred.Task: Task:attempt_local_0001_r_000000_0 is done. And is in the process of commiting
14/09/21 16:51:22 INFO mapred.LocalJobRunner:
14/09/21 16:51:22 INFO mapred.Task: Task attempt_local_0001_r_000000_0 is allowed to commit now
14/09/21 16:51:22 INFO output.FileOutputCommitter: Saved output of task 'attempt_local_0001_r_000000_0' to hdfs://localhost:9000/user/hadoop/dedup_output
14/09/21 16:51:25 INFO mapred.LocalJobRunner: reduce > reduce
14/09/21 16:51:25 INFO mapred.Task: Task 'attempt_local_0001_r_000000_0' done.
14/09/21 16:51:26 INFO mapred.JobClient: map 100% reduce 100%
14/09/21 16:51:26 INFO mapred.JobClient: Job complete: job_local_0001
14/09/21 16:51:26 INFO mapred.JobClient: Counters: 22
14/09/21 16:51:26 INFO mapred.JobClient: Map-Reduce Framework
14/09/21 16:51:26 INFO mapred.JobClient: Spilled Records=32
14/09/21 16:51:26 INFO mapred.JobClient: Map output materialized bytes=266
14/09/21 16:51:26 INFO mapred.JobClient: Reduce input records=16
14/09/21 16:51:26 INFO mapred.JobClient: Virtual memory (bytes) snapshot=0
14/09/21 16:51:26 INFO mapred.JobClient: Map input records=16
14/09/21 16:51:26 INFO mapred.JobClient: SPLIT_RAW_BYTES=232
14/09/21 16:51:26 INFO mapred.JobClient: Map output bytes=222
14/09/21 16:51:26 INFO mapred.JobClient: Reduce shuffle bytes=0
14/09/21 16:51:26 INFO mapred.JobClient: Physical memory (bytes) snapshot=0
14/09/21 16:51:26 INFO mapred.JobClient: Reduce input groups=12
14/09/21 16:51:26 INFO mapred.JobClient: Combine output records=0
14/09/21 16:51:26 INFO mapred.JobClient: Reduce output records=12
14/09/21 16:51:26 INFO mapred.JobClient: Map output records=16
14/09/21 16:51:26 INFO mapred.JobClient: Combine input records=0
14/09/21 16:51:26 INFO mapred.JobClient: CPU time spent (ms)=0
14/09/21 16:51:26 INFO mapred.JobClient: Total committed heap usage (bytes)=813170688
14/09/21 16:51:26 INFO mapred.JobClient: File Input Format Counters
14/09/21 16:51:26 INFO mapred.JobClient: Bytes Read=190
14/09/21 16:51:26 INFO mapred.JobClient: FileSystemCounters
14/09/21 16:51:26 INFO mapred.JobClient: HDFS_BYTES_READ=475
14/09/21 16:51:26 INFO mapred.JobClient: FILE_BYTES_WRITTEN=122061
14/09/21 16:51:26 INFO mapred.JobClient: FILE_BYTES_READ=1665
14/09/21 16:51:26 INFO mapred.JobClient: HDFS_BYTES_WRITTEN=166
14/09/21 16:51:26 INFO mapred.JobClient: File Output Format Counters
14/09/21 16:51:26 INFO mapred.JobClient: Bytes Written=166
5、运行结果：
2006-6-10 a
2006-6-10 b
2006-6-11 b
2006-6-11 c
2006-6-12 d
2006-6-13 a
2006-6-14 b
2006-6-14 c
2006-6-15 c
2006-6-15 d
2006-6-9 a
2006-6-9 b
2006-6-10 b
2006-6-11 b
2006-6-11 c
2006-6-12 d
2006-6-13 a
2006-6-14 b
2006-6-14 c
2006-6-15 c
2006-6-15 d
2006-6-9 a
2006-6-9 b
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