企业运维实战LAMP架构--MHA高可用集群搭建方法

1.环境搭建

需要四台虚拟机进行实验环境，其中一台负责manager，其余三台配置mysql主从复制且必须是一主二从。

具体要求：四台机器必须SSH免密登录，node端安装node相关包和依赖包，manager安装所有依赖包。

server1:
vim /etc/my.cnf

server_id=1
gtid_mode=ON
enforce_gtid_consistency=ON
master_info_repository=TABLE
relay_log_info_repository=TABLE
log_slave_updates=ON
log_bin=binlog
binlog_format=ROW

初始化mysql
rm -rf /data/mysql/*
mysqld --initialize-insecure --user=mysql
/etc/init.d/mysqld start

修改完成后进入mysql中

mysql> grant replication slave on *.* to repl@'%' identified by 'westos';
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> alter user root@localhost identified by 'westos';
Query OK, 0 rows affected (0.01 sec)
mysql> grant all on *.* to root@'%' identified by 'westos';
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

server23 同样修改配置文件并且初始化并且

mysql> change master to master_host='172.25.76.1', master_user='repl', master_password='westos', master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.03 sec)
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

server4:
将相关安装包导入至 server4

[root@foundation76 images]# scp -r /root/Desktop/westospub/docs/mysql/MHA-7/           [email protected]:/root

并将node文件传到123
scp mha4mysql-node-0.58-0.el7.centos.noarch.rpm server2/3/1:/root/
cd MHA-7
yum install *.rpm -y

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

[server default]
manager_workdir=/etc/masterha
manager_log=/etc/masterha/mha.log
master_binlog_dir=/data/mysql
#master_ip_failover_script=/usr/bin/master_ip_failover
#master_ip_online_change_script= /usr/local/bin/master_ip_online_change
user=root
password=westos
ping_interval=3
remote_workdir=/tmp
repl_user=repl
repl_password=westos
secondary_check_script=/usr/bin/masterha_secondary_check -s 172.25.76.2 -s 172.25.76.3
ssh_user=root

[server1]
hostname=172.25.76.1
port=3306

[server2]
hostname=172.25.76.2
port=3306
candidate_master=1
check_repl_delay=0

[server3]
hostname=172.25.76.3
port=3306
no_master=1              

配置四台机器互相免密登陆

master端

ssh-keygen 
ssh-copy-id server1
ssh-copy-id server2
ssh-copy-id server3
ssh-copy-id server

scp -r .ssh/ server2:
scp -r .ssh/ server3:
scp -r .ssh/ server4:

保证四台机器之间互通
server4：
检测ssh免密登陆是否正常

masterha_check_ssh --conf=/etc/masterha/app1.conf #检测ssh

检测一主二从配置是否正常

masterha_check_repl --conf=/etc/masterha/app1.conf #检测授权

若未授权，进server1主机msyql 给root用户远程登陆的权限

grant all on *.* to root@'%' identified by 'westos';

2.手动切换master

当server1(manager)处于alive模式时，在manager端进行
masterha_master_switch --conf=/etc/masterha/app1.conf --master_state=alive --new_master_host=172.25.76.2 --new_master_port=3306 --orig_master_is_new_slave --running_updates_limit=10000

进入mysql数据库show slave status\G;查看故障解决结果
当前master(server1)处于dead模式时
[root@server2 .ssh]# /etc/init.d/mysqld stop
masterha_master_switch --master_state=dead --conf=/etc/masterha/app1.conf --dead_master_host=172.25.76.2 --dead_master_port=3306 --new_master_host=172.25.76.1 --new_master_port=3306 --ignore_last_failover

3.脚本自动切换master

传入脚本

[root@foundation76 images]# scp -r /root/Desktop/westospub/docs/mysql/master_ip_online_change            [email protected]:/root
root@172.25.76.4's password: 
master_ip_online_change                       100% 3813   677.3KB/s   00:00    
[root@foundation76 images]# scp -r /root/Desktop/westospub/docs/mysql/master_ip_failover             [email protected]:/root
[email protected]'s password: 
master_ip_failover                            100% 2156   252.5KB/s   00:00    

server4：

chmod +x master_ip_*
vim master_ip_failover
vim master_ip_online_change
修改为自己的ip地址

小脚本，自动切:
masterha_manager --conf=/etc/masterha/app1.conf &
执行脚本读取文件 并打入后台，模拟master服务区down掉

将一开始注释的配置文件中的脚本选项打开
vim /etc/masterha/app1.cnf

[server default]
manager_workdir=/etc/masterha
manager_log=/etc/masterha/mha.log
master_binlog_dir=/data/mysql
master_ip_failover_script=/etc/masterha/master_ip_failover
master_ip_online_change_script=/etc/masterha/master_ip_online_change
user=root
password=westos
ping_interval=3
remote_workdir=/tmp
repl_user=repl
repl_password=westos
secondary_check_script=/usr/bin/masterha_secondary_check -s 172.25.76.2 -s 172.25.76.3
ssh_user=root
[server1]
hostname=172.25.76.1
port=3306
[server2]
hostname=172.25.76.2
port=3306
candidate_master=1
check_repl_delay=0
[server3]
hostname=172.25.76.3
port=3306
no_master=1

修改其中的VIP为自己的172.25.1.100
添加到server上 然后直接停掉server上的数据库
ip addr add 172.25.76.100/24 dev eth0
ip addr show
/etc/init.d/mysqld stop

然后可以在server4上看到刚后台执行的命令开始动作
注意这个时候刚才添加在server1上的ip172.25.76.100不在了，它飘到了server2上：
然后重新将server1启动
/etc/init.d/mysqld start
mysql -pwestos

mysql> change master to master_host='172.25.76.2', master_user='repl', master_password='westos',master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.02 sec)

mysql> start slave;
Query OK, 0 rows affected (0.00 sec)

server4:
masterha_master_switch --conf=/etc/masterha/app1.conf --master_state=alive --new_master_host=172.25.76.1 --new_master_port=3306 --orig_master_is_new_slave --running_updates_limit=10000

这个时候会发现vip 172.25.76.100又不再server2上了，飘回了server1上：