共计 5043 个字符，预计需要花费 13 分钟才能阅读完成。
Linux 执行 Hadoop WordCount
Ubuntu 终端进入快捷键：ctrl + Alt +t
hadoop 启动命令：start-all.sh
正常执行效果如下：
hadoop@HADOOP:~$ start-all.sh
Warning: $HADOOP_HOME is deprecated.
starting namenode, logging to /home/hadoop/hadoop-1.1.2/libexec/../logs/hadoop-hadoop-namenode-HADOOP.MAIN.out
HADOOP.MAIN: starting datanode, logging to/home/hadoop/hadoop-1.1.2/libexec/../logs/hadoop-hadoop-datanode-HADOOP.MAIN.out
HADOOP.MAIN: starting secondarynamenode,logging to/home/hadoop/hadoop-1.1.2/libexec/../logs/hadoop-hadoop-secondarynamenode-HADOOP.MAIN.out
starting jobtracker, logging to/home/hadoop/hadoop-1.1.2/libexec/../logs/hadoop-hadoop-jobtracker-HADOOP.MAIN.out
HADOOP.MAIN: starting tasktracker, loggingto /home/hadoop/hadoop-1.1.2/libexec/../logs/hadoop-hadoop-tasktracker-HADOOP.MAIN.out
jps 命令查看启动的 hadoop 服务
hadoop@HADOOP:~$ jps
3615 Jps
2699 NameNode
3461 TaskTracker
2922 DataNode
3137 SecondaryNameNode
3231 JobTracker
本地创建一个文件夹
hadoop@HADOOP:~$ mkdir ~/file
在 file 文件创建两个 txt 文件
hadoop@HADOOP:~$ cd file
hadoop@HADOOP:~/file$ echo “Hello World” > file1.txt
hadoop@HADOOP:~/file$ echo “Hello Hadoop” > file2.txt
hadoop@HADOOP:~/file$ ls
file1.txt file2.txt
hadoop@HADOOP:~/file$
在 HDFS 上创建一个输入文件夹
hadoop@HADOOP:~/file$ hadoop fs -mkdir input
查看创建的 input 文件夹路径
hadoop@HADOOP:~$ hadoop fs -ls
Warning: $HADOOP_HOME is deprecated.
Found 5 items
-rw-r–r– 3 Administrator supergroup 6296230 2014-09-03 10:38 /user/hadoop/cloud.txt
drwxr-xr-x – hadoop supergroup 0 2014-09-02 16:31/user/hadoop/hadi_curbm
drwxr-xr-x – hadoop supergroup 0 2014-09-04 09:59 /user/hadoop/input
drwxr-xr-x – hadoop supergroup 0 2014-09-02 16:31/user/hadoop/pegasus
hadoop@HADOOP:~$
可以看到目录被创建到 /user/hadoop/input 目录
上传本地 file 文件到 input 目录
hadoop@HADOOP:~$hadoop fs put ~/file/*.txt /user/hadoop/input
找到 hadoop 目录下的 examples.jar 程序包
hadoop@HADOOP:~$ cd hadoop-1.1.2
hadoop@HADOOP:~/hadoop-1.1.2$ ls
bin docs hadoop-test-1.1.2.jar LICENSE.txt src
build.xml hadoop-ant-1.1.2.jar hadoop-tools-1.1.2.jar logs webapps
c++ hadoop-client-1.1.2.jar ivy NOTICE.txt wordcount.jar
CHANGES.txt hadoop-core-1.1.2.jar ivy.xml README.txt
conf hadoop-examples-1.1.2.jar lib sbin
contrib hadoop-minicluster-1.1.2.jar libexec share
hadoop@HADOOP:~/hadoop-1.1.2$
执行 jar 程序代码 统计 input 目录下文件的 Wordcount
hadoop@HADOOP:~$ hadoop jar /home/hadoop/hadoop-1.1.2/hadoop-examples-1.1.2.jar wordcount /user/hadoop/input output
Warning: $HADOOP_HOME is deprecated.
14/09/04 10:10:44 INFOinput.FileInputFormat: Total input paths to process : 0
14/09/04 10:10:45 INFO mapred.JobClient:Running job: job_201409040943_0001
14/09/04 10:10:46 INFOmapred.JobClient: map 0% reduce 0%
14/09/04 10:10:54 INFOmapred.JobClient: map 0% reduce 100%
14/09/04 10:10:55 INFO mapred.JobClient:Job complete: job_201409040943_0001
14/09/04 10:10:55 INFO mapred.JobClient:Counters: 18
14/09/04 10:10:55 INFOmapred.JobClient: Job Counters
14/09/04 10:10:55 INFOmapred.JobClient: Launched reducetasks=1
14/09/04 10:10:55 INFOmapred.JobClient: SLOTS_MILLIS_MAPS=4087
14/09/04 10:10:55 INFOmapred.JobClient: Total time spent byall reduces waiting after reserving slots (ms)=0
14/09/04 10:10:55 INFOmapred.JobClient: Total time spent byall maps waiting after reserving slots (ms)=0
14/09/04 10:10:55 INFO mapred.JobClient: SLOTS_MILLIS_REDUCES=4068
14/09/04 10:10:55 INFOmapred.JobClient: File Output FormatCounters
14/09/04 10:10:55 INFOmapred.JobClient: Bytes Written=0
14/09/04 10:10:55 INFOmapred.JobClient: FileSystemCounters
14/09/04 10:10:55 INFO mapred.JobClient: FILE_BYTES_WRITTEN=55309
14/09/04 10:10:55 INFOmapred.JobClient: Map-Reduce Framework
14/09/04 10:10:55 INFOmapred.JobClient: Reduce inputgroups=0
14/09/04 10:10:55 INFOmapred.JobClient: Combine outputrecords=0
14/09/04 10:10:55 INFOmapred.JobClient: Reduce shufflebytes=0
14/09/04 10:10:55 INFOmapred.JobClient: Physical memory(bytes) snapshot=35037184
14/09/04 10:10:55 INFOmapred.JobClient: Reduce outputrecords=0
14/09/04 10:10:55 INFO mapred.JobClient: Spilled Records=0
14/09/04 10:10:55 INFOmapred.JobClient: CPU time spent(ms)=120
14/09/04 10:10:55 INFOmapred.JobClient: Total committedheap usage (bytes)=15925248
14/09/04 10:10:55 INFOmapred.JobClient: Virtual memory(bytes) snapshot=377499648
14/09/04 10:10:55 INFOmapred.JobClient: Combine inputrecords=0
14/09/04 10:10:55 INFOmapred.JobClient: Reduce inputrecords=0
hadoop@HADOOP:~$
显示结果
hadoop@HADOOP:~$ hadoop fs -ls output
Warning: $HADOOP_HOME is deprecated.
Found 3 items
-rw-r–r– 1 hadoop supergroup 02014-09-04 10:10 /user/hadoop/output/_SUCCESS
drwxr-xr-x – hadoop supergroup 02014-09-04 10:10 /user/hadoop/output/_logs
-rw-r–r– 1 hadoop supergroup 02014-09-04 10:10 /user/hadoop/output/part-r-00000
hadoop@HADOOP:~$
查看执行结果
hadoop@HADOOP:~$ hadoop fs -cat output/part-r-00000
Hadoop 1
Hello 2
World 1
Ubuntu 13.04 上搭建 Hadoop 环境 http://www.linuxidc.com/Linux/2013-06/86106.htm
Ubuntu 12.10 +Hadoop 1.2.1 版本集群配置 http://www.linuxidc.com/Linux/2013-09/90600.htm
Ubuntu 上搭建 Hadoop 环境（单机模式 + 伪分布模式）http://www.linuxidc.com/Linux/2013-01/77681.htm
Ubuntu 下 Hadoop 环境的配置 http://www.linuxidc.com/Linux/2012-11/74539.htm
单机版搭建 Hadoop 环境图文教程详解 http://www.linuxidc.com/Linux/2012-02/53927.htm
搭建 Hadoop 环境（在 Winodws 环境下用虚拟机虚拟两个 Ubuntu 系统进行搭建）http://www.linuxidc.com/Linux/2011-12/48894.htm
更多 Hadoop 相关信息见 Hadoop 专题页面 http://www.linuxidc.com/topicnews.aspx?tid=13
