[server1]
hostname = 192.168.3.27
master_binlog_dir = /data/lib/mysql
candidate_master = 1

[server2]
hostname = 192.168.3.28
master_binlog_dir = /data/lib/mysql
candidate_master =1

[server3]
hostname = 192.168.3.25
no_master = 1

3.配置SSH等效连接

因为MHA管理节点以及各个Node节点之间需要无密码登录并执行相关脚本，所以需要配置各个节点之间的SSH等效性，如下：
??生成密钥文件（各个节点均需执行）

# mkdir -p ~/.ssh
# cd .ssh
# /usr/bin/ssh-keygen -t rsa （提示处直接回车即可）
# /usr/bin/ssh-keygen -t dsa （提示处直接回车即可）
执行完成后，在/root/.ssh 目录下会生产四个密钥文件。

??任意一个节点执行即可（本例选择在manager节点执行）

# ssh 192.168.3.27 cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
# ssh 192.168.3.27 cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
# ssh 192.168.3.28 cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
# ssh 192.168.3.28 cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
# ssh 192.168.3.25 cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
# ssh 192.168.3.25 cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
# ssh 192.168.3.26 cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
# ssh 192.168.3.26 cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
# scp ~/.ssh/authorized_keys 192.168.3.27:.ssh/
# scp ~/.ssh/authorized_keys 192.168.3.28:.ssh/
# scp ~/.ssh/authorized_keys 192.168.3.25:.ssh/

??修改authorized_keys文件的权限为600（所有节点均需执行）
# chmod 600 ~/.ssh/authorized_keys

??测试一下
在各节点执行如下命令，测试一下，看是否不提示密码即可显示，否则则说明SSH配置不成功。
# ssh 192.168.3.26 hostname
# ssh 192.168.3.26 date

另外，还可采用MHA提供的工具命令来检查，如下：
[root@mmm .ssh]# /usr/bin/masterha_check_ssh --conf=/etc/appl.cnf
Fri Jul 18 16:52:12 2014 - [info] Reading default configuratoins from /etc/masterha_default.cnf..
Fri Jul 18 16:52:12 2014 - [info] Reading application default configurations from /etc/appl.cnf..
Fri Jul 18 16:52:12 2014 - [info] Reading server configurations from /etc/appl.cnf..
Fri Jul 18 16:52:12 2014 - [info] Starting SSH connection tests..
Fri Jul 18 16:52:13 2014 - [debug]
Fri Jul 18 16:52:12 2014 - [debug] Connecting via SSH from root@192.168.3.27(192.168.3.27:22) to root@192.168.3.28(192.168.3.28:22)..
Fri Jul 18 16:52:12 2014 - [debug] ok.
Fri Jul 18 16:52:12 2014 - [debug] Connecting via SSH from root@192.168.3.27(192.168.3.27:22) to root@192.168.3.25(192.168.3.25:22)..
Fri Jul 18 16:52:12 2014 - [debug] ok.
Fri Jul 18 16:52:13 2014 - [debug]
Fri Jul 18 16:52:12 2014 - [debug] Connecting via SSH from root@192.168.3.28(192.168.3.28:22) to root@192.168.3.27(192.168.3.27:22)..
Fri Jul 18 16:52:13 2014 - [debug] ok.
Fri Jul 18 16:52:13 2014 - [debug] Connecting via SSH from root@192.168.3.28(192.168.3.28:22) to root@192.168.3.25(192.168.3.25:22)..
Fri Jul 18 16:52:13 2014 - [debug] ok.
Fri Jul 18 16:52:13 2014 - [debug]
Fri Jul 18 16:52:13 2014 - [debug] Connecting via SSH from root@192.168.3.25(192.168.3.25:22) to root@192.168.3.27(192.168.3.27:22)..
Fri Jul 18 16:52:13 2014 - [debug] ok.
Fri Jul 18 16:52:13 2014 - [debug] Connecting via SSH from root@192.168.3.25(192.168.3.25:22) to root@192.168.3.28(192.168.3.28:22)..
Fri Jul 18 16:52:13 2014 - [debug] ok.
Fri Jul 18 16:52:13 2014 - [info] All SSH connection tests passed successfully.

从中可以看到，该命令会从应用配置文件中读取相关信息（IP和SSH_USER），然后在各个Node之间相互验证，保证可以通过SSH方式相互登录（用于同步差异日志）。

4.配置hosts解析