Hadoop运行单词统计

1.创建input文件夹

hadoop fs -mkdir input

2.上传文件到hadoop

hadoop fs -put /root/data/output.txt input

3.运行wordcount（运行前删除旧的output文件夹，可以使用eclipse删除）

hadoop jar ./hadoop-examples-1.2.1.jar wordcount input output

4.下载文件到本地

hadoop fs -get output /root/data/

运行结果：

[root@VM_238_215_centos hadoop-1.2.1]# hadoop jar ./hadoop-examples-1.2.1.jar wordcount input output
Warning: $HADOOP_HOME is deprecated.

17/05/08 13:31:19 INFO input.FileInputFormat: Total input paths to process : 1
17/05/08 13:31:19 INFO util.NativeCodeLoader: Loaded the native-hadoop library
17/05/08 13:31:19 WARN snappy.LoadSnappy: Snappy native library not loaded
17/05/08 13:31:20 INFO mapred.JobClient: Running job: job_201705080035_0003
17/05/08 13:31:21 INFO mapred.JobClient:  map 0% reduce 0%
17/05/08 13:31:27 INFO mapred.JobClient:  map 100% reduce 0%
17/05/08 13:31:34 INFO mapred.JobClient:  map 100% reduce 33%
17/05/08 13:31:36 INFO mapred.JobClient:  map 100% reduce 100%
17/05/08 13:31:37 INFO mapred.JobClient: Job complete: job_201705080035_0003
17/05/08 13:31:37 INFO mapred.JobClient: Counters: 29
17/05/08 13:31:37 INFO mapred.JobClient:   Map-Reduce Framework
17/05/08 13:31:37 INFO mapred.JobClient:     Spilled Records=8008
17/05/08 13:31:37 INFO mapred.JobClient:     Map output materialized bytes=51608
17/05/08 13:31:37 INFO mapred.JobClient:     Reduce input records=4004
17/05/08 13:31:37 INFO mapred.JobClient:     Virtual memory (bytes) snapshot=587849728
17/05/08 13:31:37 INFO mapred.JobClient:     Map input records=1
17/05/08 13:31:37 INFO mapred.JobClient:     SPLIT_RAW_BYTES=118
17/05/08 13:31:37 INFO mapred.JobClient:     Map output bytes=203949
17/05/08 13:31:37 INFO mapred.JobClient:     Reduce shuffle bytes=51608
17/05/08 13:31:37 INFO mapred.JobClient:     Physical memory (bytes) snapshot=196730880
17/05/08 13:31:37 INFO mapred.JobClient:     Reduce input groups=4004
17/05/08 13:31:37 INFO mapred.JobClient:     Combine output records=4004
17/05/08 13:31:37 INFO mapred.JobClient:     Reduce output records=4004
17/05/08 13:31:37 INFO mapred.JobClient:     Map output records=19391
17/05/08 13:31:37 INFO mapred.JobClient:     Combine input records=19391
17/05/08 13:31:37 INFO mapred.JobClient:     CPU time spent (ms)=1230
17/05/08 13:31:37 INFO mapred.JobClient:     Total committed heap usage (bytes)=177016832
17/05/08 13:31:37 INFO mapred.JobClient:   File Input Format Counters 
17/05/08 13:31:37 INFO mapred.JobClient:     Bytes Read=126386
17/05/08 13:31:37 INFO mapred.JobClient:   FileSystemCounters
17/05/08 13:31:37 INFO mapred.JobClient:     HDFS_BYTES_READ=126504
17/05/08 13:31:37 INFO mapred.JobClient:     FILE_BYTES_WRITTEN=213603
17/05/08 13:31:37 INFO mapred.JobClient:     FILE_BYTES_READ=51608
17/05/08 13:31:37 INFO mapred.JobClient:     HDFS_BYTES_WRITTEN=35986
17/05/08 13:31:37 INFO mapred.JobClient:   Job Counters 
17/05/08 13:31:37 INFO mapred.JobClient:     Launched map tasks=1
17/05/08 13:31:37 INFO mapred.JobClient:     Launched reduce tasks=1
17/05/08 13:31:37 INFO mapred.JobClient:     SLOTS_MILLIS_REDUCES=9105
17/05/08 13:31:37 INFO mapred.JobClient:     Total time spent by all reduces waiting after reserving slots (ms)=0
17/05/08 13:31:37 INFO mapred.JobClient:     SLOTS_MILLIS_MAPS=5744
17/05/08 13:31:37 INFO mapred.JobClient:     Total time spent by all maps waiting after reserving slots (ms)=0
17/05/08 13:31:37 INFO mapred.JobClient:     Data-local map tasks=1
17/05/08 13:31:37 INFO mapred.JobClient:   File Output Format Counters 
17/05/08 13:31:37 INFO mapred.JobClient:     Bytes Written=35986