修改mapred-site.xml
<?xml version="1.0"?><?xml-stylesheet type="text/xsl" href="https://www.linuxidc.com/configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>mapred.job.tracker</name>
<value>http://master:9001</value>
</property>
</configuration> mapred.job.tracker，设置jobtracker所在机器，端口号9001
修改masters
master
虽然masters内写的是master，但是个人感觉，这个并不是指定master节点，而是配置secondaryNameNode
修改slaves
master slave1 slave2配置了集群中所有slave节点
④ 添加Hadoop环境变量，并 source ~/.bash_profile使之生效
export JAVA_HOME=/root/bin/jdk1.6.0_32 export HADOOP_HOME=/root/bin/hadoop-0.20.2 export PATH=$PATH:$JAVA_HOME/bin:$HADOOP_HOME/bin
⑤ 将已经配置好的hadoop-0.20.2，分别拷贝到另外两台主机，并做相同配置
⑥ 此时，hadoop的集群配置已经完成，输入hadoop，则可看到hadoop相关的操作
[root@master ~]# hadoop Usage: hadoop [--config confdir] COMMAND where COMMAND is one of: namenode -format format the DFS filesystem secondarynamenode run the DFS secondary namenode namenode run the DFS namenode datanode run a DFS datanode dfsadmin run a DFS admin client mradmin run a Map-Reduce admin client fsck run a DFS filesystem checking utility fs run a generic filesystem user client balancer run a cluster balancing utility jobtracker run the MapReduce job Tracker node pipes run a Pipes job tasktracker run a MapReduce task Tracker node job manipulate MapReduce jobs queue get information regarding JobQueues version print the version jar <jar> run a jar file distcp <srcurl> <desturl> copy file or directories recursively archive -archiveName NAME <src>* <dest> create a hadoop archive daemonlog get/set the log level for each daemon or CLASSNAME run the class named CLASSNAME Most commands print help when invoked w/o parameters.
⑦ 此时，首先格式化hadoop在命令行里执行，hadoop namenode -format