MySQL MHA 的vip功能及故障演练

MHA 的vip功能

修改脚本内容

[root@db03 bin]# vi /usr/local/bin/master_ip_failover
my $vip = '10.0.0.205/24'; ###同一网段，不能占用
my $key = '1';####相当于设置系统临时地址（ifconfig eth0:1 10.0.0.205/24）,取消ifconfig eth0:1 down
my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig eth0:$key down";
[root@db03 bin]# chmod +x /usr/local/bin/master_ip_failover ####添加权限
[root@db03 bin]# dos2unix /usr/local/bin/master_ip_failover 去除脚本中的中文字符

更改manager配置文件

vi /etc/mha/app1.cnf
添加：
master_ip_failover_script=/usr/local/bin/master_ip_failover

主库上，手工生成第一个vip地址

手工在主库上绑定vip，注意一定要和配置文件中的ethN一致，我的是eth0:1(1是key指定的值)
[root@db02 ~]# ifconfig eth0:1 10.0.0.205/24
[root@db02 ~]# ip a
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 
inet 10.0.0.205/24 brd 10.0.0.255 scope global secondary eth0:1
valid_lft forever preferred_lft forever

重启mha

[root@db03 bin]#masterha_stop --conf=/etc/mha/app1.cnf
[root@db03 bin]#nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf 
--ignore_last_failover < /dev/null > /var/log/mha/app1/manager.log 2>&1 &
[root@db03 ~]# masterha_check_status --conf=/etc/mha/app1.cnf

VIP故障模拟及恢复

故障模拟

[root@db02 ~]# pkill mysql
[root@db01 ~]# ifconfig
eth0:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.0.0.205 netmask 255.255.255.0 broadcast 10.0.0.255
db03 [(none)]>show slave status \G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 10.0.0.200

故障恢复

[root@db02 ~]# systemctl start mysqld
[root@db03 bin]# cat /var/log/mha/app1/manager
CHANGE MASTER TO MASTER_HOST='10.0.0.200', MASTER_PORT=3306, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';
db02 [(none)]>CHANGE MASTER TO MASTER_HOST='10.0.0.200', MASTER_PORT=3306, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';
db02 [(none)]>start slave;
[root@db03 bin]# vim /etc/mha/app1.cnf
添加
[server2]
hostname=10.0.0.201
port=3306

重启mha

[root@db03 bin]#nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/mha/app1/manager.log 2>&1 &
[root@db03 ~]# masterha_check_status --conf=/etc/mha/app1.cnf