Hadoop单机环境搭建

说明：单机环境—仅仅适用于单击运行分布式计算作业，直接执行mapreduce-examples.jar案例。

1.首先到官网下载好hadoop压缩包，上传到Linux上，解压

2.修改主机名

[[email protected] ~]# hostnamectl set-hostname server
[[email protected] ~]# reboot    #重启生效

3.设置主机与ip间的映射

[[email protected] ~]# vim /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.2.100 server

4.新建一个输出目录

[[email protected] ~]# cd hadoop/hadoop-2.7.3/
[[email protected] hadoop-2.7.3]# mkdir input

5.拷贝etc/hadoop/下的.xml文件到输出目录

[[email protected] hadoop-2.7.3]# cp etc/hadoop/*.xml input/
[[email protected] hadoop-2.7.3]# ls input/
capacity-scheduler.xml  hadoop-policy.xml  httpfs-site.xml  kms-site.xml
core-site.xml           hdfs-site.xml      kms-acls.xml     yarn-site.xml
[[email protected] hadoop-2.7.3]# 

6.运行hadoop简单案例
格式：/bin/hadoop jar 案例的相对路径 主方法 输入目录 输出目录 正则表达式（输出目录不需要创建，执行会自动创建）

[[email protected] hadoop-2.7.3]# bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.3.jar grep input/ output 'dfs[a-z.]+'
		Total committed heap usage (bytes)=1399808000
	Shuffle Errors
		BAD_ID=0
		CONNECTION=0
		IO_ERROR=0
		WRONG_LENGTH=0
		WRONG_MAP=0
		WRONG_REDUCE=0
	File Input Format Counters 
		Bytes Read=26007
	File Output Format Counters 
		Bytes Written=123

7.查看输出目录，_SUCCESS说明案例运行成功

[[email protected] hadoop-2.7.3]# ls output/
part-r-00000  _SUCCESS
[[email protected] hadoop-2.7.3]#