MHA的安装搭建步骤

安装基本环境：
master:192.168.0.1
node:192.168.0.2 192.168.0.3
vip:192.168.0.101

1、机器添加ssh信任

ssh-keygen
cat ~/.ssh/ip_rsa.pub >> ~/.ssh/authorized.keys
rm kown_hosts
chomod  600 authorized.keys
scp –r .ssh 192.168.0.2:~/
scp -r .ssh  192.168.0.3:~/ 

2、下载mha

master：https://github.com/yoshinorim/mha4mysql-manager/releases
node：https://github.com/yoshinorim/mha4mysql-node/releases

3、在三台机器中安装依赖

安装epel源
yum install -y epel-release
安装perl
yum install perl-DBD-MySQL
yum install perl-Config-Tiny
yum install perl-Log-Dispatch
yum install perl-Parallel-ForkManager

4、安装mysql，部署主从结构

master 192.168.0.1 >> slave:192.168.0.2 192.168.0.3
创建mha账号

5、安装mha node

在manager节点和node节点中都需要安装mha node
rpm包安装方式：
yum localinstall -y mha4mysql-node-0.58-0.el7.centos.noarch.rpm

6、安装mha manager

只在manager节点上安装
rpm包安装方式：
yum localinstall -y mha4mysql-manager-0.58-0.el7.centos.noarch.rpm

7、MHA manager配置

mkdir /etc/masterha
vim /etc/masterha/app1.conf

[server default]
#mha manager 工作目录
manager_workdir = /var/log/masterha/app1
manager_log = /var/log/masterha/app1/app1.log 
remote_workdir = /var/log/masterha/app1

[server1]
hostname=192.168.0.1
master_binlog_dir = /data/mysql/mysql3306/logs
candidate_master = 1
check_repl_delay = 0       

[server2]
hostname=192.168.0.2
master_binlog_dir=/data/mysql/mysql3306/logs 
candidate_master=1
check_repl_delay=0

[server3]
hostname=192.168.0.3
master_binlog_dir=/data/mysql/mysql3306/logs 
candidate_master=1
check_repl_delay=0

全局配置文件
vim /etc/masterha/masterha_defaults.conf

[server default]
#MySQL的用户和密码
user=root
password=root

#系统ssh用户
ssh_user=root

#复制用户
repl_user=repl
repl_password=repl4slave

#监控
ping_interval=1
#shutdown_script=""

#切换调用的脚本
#master_ip_failover_script=/etc/masterha/master_ipfailover
#master_ip_online_change_script=/etc/masterha/master_ip_online_change

8、vip配置

绑定和删除vip节点

[root@master masterha]# cat init_vip.sh 
vip="192.168.0.101/32"
/sbin/ip addr add $vip dev eth0

root@master masterha]# cat drop_vip.sh 
vip="192.168.0.101/32"
/sbin/ip addr del $vip dev eth0

配置vip故障切换脚本

master_ip_failover：https://github.com/yoshinorim/mha4mysql-manager/blob/master/samples/scripts/master_ip_failover
master_ip_online_change:https://github.com/yoshinorim/mha4mysql-manager/blob/master/samples/scripts/master_ip_online_change
根据作者的脚本来进行改写配置。

9、测试配置文件

测试ssh

masterha_check_ssh --global-conf=/etc/masterha/masterha_default.conf --conf=/etc/masterha/app1.conf

测试主从结构，能不能启动

masterha_check_slave --global-conf=/etc/masterha/masterha_default.conf --conf=/etc/masterha/app1.conf

报错：
[/usr/local/share/perl5/MHA/MasterMonitor.pm,ln205] Slaves settings check failed!
[/usr/local/share/perl5/MHA/MasterMonitor.pm,ln413] Slave configuration failed.
[/usr/local/share/perl5/MHA/MasterMonitor.pm,ln424] Error happened on checking configurations. at /usr/local/bin/masterha_check_repl line 48
[/usr/local/share/perl5/MHA/MasterMonitor.pm,ln523] Error happened on monitoring servers.
[info] Got exit code 1 (Not master dead).

MySQL Replication Health is NOT OK!
在所有节点执行:
ln -s /usr/local/mysql/bin/mysql /usr/bin/mysql

执行后再次报错:
[info] Connecting to root@192.168.0.1(192.168.0.1:22)..
Can't exec "mysqlbinlog": No suchfile or directory at /usr/local/share/perl5/MHA/BinlogManager.pm line 106.
mysqlbinlog version command failed with rc1:0, please verify PATH, LD_LIBRARY_PATH, and client options
at/usr/local/bin/apply_diff_relay_logs line 493
[/usr/local/share/perl5/MHA/MasterMonitor.pm,ln205] Slaves settings check failed!
[/usr/local/share/perl5/MHA/MasterMonitor.pm,ln413] Slave configuration failed.
[/usr/local/share/perl5/MHA/MasterMonitor.pm,ln424] Error happened on checking configurations. at /usr/local/bin/masterha_check_repl line 48
[/usr/local/share/perl5/MHA/MasterMonitor.pm,ln523] Error happened on monitoring servers.
Got exit code 1 (Not master dead).
MySQL Replication Health is NOT OK!
在所有节点执行
[root@master masterha]#type mysqlbinlog
[root@master masterha]#mysqlbinlog is/usr/local/mysql/bin/mysqlbinlog
[root@master masterha]#ln -s/usr/local/mysql/bin/mysqlbinlog /usr/bin/mysqlbinlog
原因：都是没有在指定位置找到相应的文件，所以做一个软链

10、MHA启动和关闭

启动：
第一次，手动绑定vip
sh /etc/masterha/init_vip.sh

masterha_manager --global_conf=/etc/masterha/masterha_default.conf --conf=/etc/masterha/app1.conf &

检查MHA是否启动和状态
cat /var/log/masterha/app1.log

masterha_check_status --global_conf=/etc/masterha/masterha_default.conf --conf=/etc/masterha/app1.conf

停止：

masterha_stop --global_conf=/etc/masterha/masterha_default.conf --conf=/etc/masterha/app1.conf