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..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.]# hadoop jar ./hadoop-examples-1.2..jar wordcount input output
Warning: $HADOOP_HOME is deprecated.

// :: INFO input.FileInputFormat: Total input paths to process :
// :: INFO util.NativeCodeLoader: Loaded the native-hadoop library
// :: WARN snappy.LoadSnappy: Snappy native library not loaded
// :: INFO mapred.JobClient: Running job: job_201705080035_0003
// :: INFO mapred.JobClient:  map % reduce %
// :: INFO mapred.JobClient:  map % reduce %
// :: INFO mapred.JobClient:  map % reduce %
// :: INFO mapred.JobClient:  map % reduce %
// :: INFO mapred.JobClient: Job complete: job_201705080035_0003
// :: INFO mapred.JobClient: Counters:
// :: INFO mapred.JobClient:   Map-Reduce Framework
// :: INFO mapred.JobClient:     Spilled Records=
// :: INFO mapred.JobClient:     Map output materialized bytes=
// :: INFO mapred.JobClient:     Reduce input records=
// :: INFO mapred.JobClient:     Virtual memory (bytes) snapshot=
// :: INFO mapred.JobClient:     Map input records=
// :: INFO mapred.JobClient:     SPLIT_RAW_BYTES=
// :: INFO mapred.JobClient:     Map output bytes=
// :: INFO mapred.JobClient:     Reduce shuffle bytes=
// :: INFO mapred.JobClient:     Physical memory (bytes) snapshot=
// :: INFO mapred.JobClient:     Reduce input groups=
// :: INFO mapred.JobClient:     Combine output records=
// :: INFO mapred.JobClient:     Reduce output records=
// :: INFO mapred.JobClient:     Map output records=
// :: INFO mapred.JobClient:     Combine input records=
// :: INFO mapred.JobClient:     CPU time spent (ms)=
// :: INFO mapred.JobClient:     Total committed heap usage (bytes)=
// :: INFO mapred.JobClient:   File Input Format Counters
// :: INFO mapred.JobClient:     Bytes Read=
// :: INFO mapred.JobClient:   FileSystemCounters
// :: INFO mapred.JobClient:     HDFS_BYTES_READ=
// :: INFO mapred.JobClient:     FILE_BYTES_WRITTEN=
// :: INFO mapred.JobClient:     FILE_BYTES_READ=
// :: INFO mapred.JobClient:     HDFS_BYTES_WRITTEN=
// :: INFO mapred.JobClient:   Job Counters
// :: INFO mapred.JobClient:     Launched map tasks=
// :: INFO mapred.JobClient:     Launched reduce tasks=
// :: INFO mapred.JobClient:     SLOTS_MILLIS_REDUCES=
// :: INFO mapred.JobClient:     Total time spent by all reduces waiting after reserving slots (ms)=
// :: INFO mapred.JobClient:     SLOTS_MILLIS_MAPS=
// :: INFO mapred.JobClient:     Total time spent by all maps waiting after reserving slots (ms)=
// :: INFO mapred.JobClient:     Data-local map tasks=
// :: INFO mapred.JobClient:   File Output Format Counters
// :: INFO mapred.JobClient:     Bytes Written=