单机版 hadoop 云平台（伪分布式）搭建 统计单词

1.首先需要配置java环境

​​CentOS安装java jdk教程​​

2.上传hadoop到/usr/local目录 并解压

cd /usr/local

ls

​​linux上传下载文件教程​

3.配置hadoop环境目录

vim /etc/profile

#java environment
export JAVA_HOME=/usr/local/jdk1.8.0_151
export JRE_HOME=/usr/local/jdk1.8.0_151/jre
#export PATH=$PATH:/usr/local/jdk1.8.0_151/bin
export CLASSPATH=./:$JAVA_HOME/lib:$JRE_HOME/lib

#hadoop environment
export HADOOP_HOME=/usr/local/hadoop-2.8.4
export PATH=$PATH:$JAVA_HOME/bin:$HADOOP_HOME/bin:$HADOOP_HOME/sbin:

4.在hadoop配置文件 配置java jdk

vim /usr/local/hadoop-2.8.4/etc/hadoop/hadoop-env.sh

source /usr/local/hadoop-2.8.4/etc/hadoop/hadoop-env.sh

# The java implementation to use.
export JRE_HOME=/usr/local/jdk1.8.0_151

5.查看

which hadoop

hadoop version

6.统计单词

这里统计的是 /root/input/a.txt 文件，并且将结果存放到 /root/output 目录

hadoop jar /usr/local/hadoop-2.8.4/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.8.4.jar wordcount /root/input/a.txt /root/output

7.查看结果

cd /root/output