hadoop 网络配置，环境变量参数

根据 IP 分配表的内容分别修改各主机的网卡配置文件

vi /etc/sysconfig/network-scripts/ifcfg-eth0
NAME="System eth0"
IPADDR=92.16.20.2
GATEWAY=255.255.248.0
NM_CONTROLLED=yes
ONBOOT=yes
BOOTPROTO=none
USERCTL=no
IPV6INIT=no
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
service network reload

分别修改和主机的 host 文件

vi /etc/hosts
92.16.20.1 hadoop1
92.16.20.2 hadoop2
92.16.20.3 hadoop3

编辑 sshd_config 配置文件，将三个参数 RSAAuthentication, PubkeyAuthentication,

AuthorizedKeysFile 的注释撤销掉，之后停止并再次启动 SSHD 守护进程

vi /etc/ssh/sshd_config
RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile      .ssh/authorized_keys

再次切换到 root 用户，修改 /etc/profile 配置文件

vi /etc/profile
export JAVA_HOME=/usr/lib/java/jdk1.7.0_79
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

编辑 /etc/profile 文件

vi /etc/profile

export HADOOP_HOME=/app/hadoop/hadoop-2.6.4
export HADOOP_INSTALL=$HADOOP_HOME
export HADOOP_MAPRED_HOME=$HADOOP_HOME
export HADOOP_COMMON_HOME=$HADOOP_HOME
export HADOOP_HDFS_HOME=$HADOOP_HOME
export YARN_HOME=$HADOOP_HOME
export HADOOP_YARN_HOME=$HADOOP_HOME
export HADOOP_CONF_DIR=$HADOOP_HOME/etc/hadoop
export HADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_HOME/lib/native
export PATH=$PATH:$HADOOP_HOME/sbin:$HADOOP_HOME/bin:$HOME/bin:$JAVA_HOME/bin:$HOME/bin