yum remove java* libreoffice* -y
2. 关闭防火墙,SELINUX
systemctl stop firewalld.service
systemctl disable firewalld.service
编辑文件/etc/selinux/config
SELINUX=enforcing 改为 SELINUX= disabled
3. 设置SSH免密码登陆
输入命令，ssh-keygen -t rsa ，生成key，一直回车，/root就会生成.ssh文件夹
接下来执行以下命令
cat id_rsa.pub >> authorized_keys
chmod 644 ~/.ssh/authorized_keys
chmod 744 ~/.ssh/
systemctl enable sshd.service
scp -rp authorized_keys 客户端IP:/root/.ssh/
（scp没有.ssh目录，使用客户端ssh连接一下服务端即生成该文件夹）
三台hadoop集群:
192.168.159.151 master
192.168.159.152 slave1
192.168.159.153 slave2
修改主机名hostname（客户端服务端均修改）
[root@master ~]# cat /etc/sysconfig/network（永久修改）
# Created by anaconda
NETWORKING=yes
HOSTNAME=master
hostnamectl set-hostname [主机名]
例 ：hostnamectl set-hostname master
修改/etc/hosts
格式为:
[root@slave1 /]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.159.151 master
192.168.159.152 slave1
192.168.159.153 slave2
解压包:
cd /usr/local/src/;rz -yb 上传hadoop-1.2.1-bin.tar.gz和jdk-6u45-linux-x64.bin
tar zxvf hadoop-1.2.1-bin.tar.gz;./jdk-6u45-linux-x64.bin
拷贝到各节点:
scp -rp jdk1.6.0_45 slave1:/usr/local/src/
cd /usr/local/src/jdk1.6.0_45/bin;./java
vi ~/.bashrc
加入JAVA的环境变量:
export JAVA_HOME=/usr/local/src/jdk1.6.0_45
export CLASSPATH=.:CLASSPATH:JAVA_HOME/lib
export PATH=$PATH:$JAVA_HOME/bin
source ~/.bashrc
hadoop安装:
cd /usr/local/src/hadoop-1.2.1
mkdir tmp(存放临时文件，core-site.xml 配置文件指定其pwd路径)
cd /usr/local/src/hadoop-1.2.1/conf
修改masters,slaves文件:
[root@master conf]# cat masters
master
[root@master conf]# cat slaves
slave1
slave2
[root@master conf]# cat hdfs-site.xml
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>dfs.replication</name>
<value>3</value>
</property>
</configuration>
[root@master conf]# cat core-site.xml
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>hadoop.tmp.dir</name>
<value>/usr/local/src/hadoop-1.2.1/tmp</value>
</property>
<property>
<name>fs.default.name</name>
<value>hdfs://192.168.159.151:9000</value>
</property>
</configuration>
[root@master conf]# cat hdfs-site.xml
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>dfs.replication</name>
<value>3</value>
</property>
</configuration>
[root@master conf]# cat mapred-site.xml
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>mapred.job.tracker</name>
<value>http://192.168.159.151:9001</value>
</property>
</configuration>
在hadoop-env.sh加入一行JAVA_HOME的环境变量:
export JAVA_HOME=/usr/local/src/jdk1.6.0_45
master执行:
然后将服务端的hadoop-1.2.1目录scp到各客户端:
scp -rp /usr/local/src/hadoop-1.2.1 slave1:/usr/local/src/
cd /usr/local/src/hadoop-1.2.1/bin
格式化namenode:
./hadoop namenode -format
启动各节点:
./start-all.sh
设置开机自动启动hadoop各节点，和生成hadoop启动命令的环境变量:
cat /root/.bashrc
export JAVA_HOME=/usr/local/src/jdk1.6.0_45
export HADOOP_HOME=/usr/local/src/hadoop-1.2.1
#export PATH=.:$HADOOP_HOME/bin:$JAVA_HOME/bin:$PATH
$PATH换成现在定义的环境变量即可， : 用来分隔环境变量
export PATH=$PATH:$JAVA_HOME/bin:/usr/local/src/hadoop-1.2.1/bin
cat .bash_profile
在.bash_profile里面追加一行:
export HADOOP_HOME_WARN_SUPPRESS=1
启动Hadoop时报了一个警告信息，我的系统是CentOS，安装的Hadoop版本是hadoop1.2.1，具体警告信息如下：
bin/start-all.sh Warning: $HADOOP_HOME is deprecated.
网上的说法是因为Hadoop本身对HADOOP_HOME做了判断，具体在bin/hadoop和bin/hadoop-config.sh里。在hadoop-config.sh里有如下的配置：
if [ "$HADOOP_HOME_WARN_SUPPRESS" = "" ] && [ "$HADOOP_HOME" != "" ]; then echo "Warning: \$HADOOP_HOME is deprecated." 1>&2 echo 1>&2fi
2. 在当前用户目录下的 .bash_profile 里增加一个环境变量：
export HADOOP_HOME_WARN_SUPPRESS=1 注：修改完 .bash_profile 后需要执行 source 操作使其生效
master查看启动的节点
[root@master hadoop-1.2.1]# jps
5676 Jps
3237 JobTracker
3158 SecondaryNameNode
2994 NameNode
slave查看启动的节点:
[root@slave1 ~]# jps
2673 DataNode
3346 Jps
2757 TaskTracker
查看hdfs
./hadoop fs -ls /
上传文件
./hadoop fs -put /etc/passwd /
查看上传的文件
./hadoop fs -cat /passwd
