MHA主库切换
作者:互联网
1.MHA主库切换机制
1.读取配置中的指定优先级
candidate_master=1
check_repl_delay=0
2.如果数据量不同,数据量多的为主库
3.如果数据量相同,按照主机标签,值越小优先级越高 # 不问顺序
2.主机标签优先级测试
#配置MHA
[root@db03 ~]# vim /service/mha/app1.cnf
......
[serverc]
hostname=172.16.1.53
port=3306
[serverb]
hostname=172.16.1.52
port=3306
[serverd]
hostname=172.16.1.51
port=3306
......
#停掉主库,查看切换
mysql> show slave status\G
Master_Host: 172.16.1.52
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
3.指定优先级测试
#配置优先级
[root@db03 ~]# vim /service/mha/app1.cnf
......
[server3]
candidate_master=1
check_repl_delay=0
hostname=172.16.1.53
port=3306
......
#停掉主库,查看切换
mysql> show slave status\G
Master_Host: 172.16.1.53
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
4.数据量不同时切换的优先级
1.主库建库
mysql> use test
Database changed
mysql> create table linux9(id int not null primary key auto_increment,name varchar(10));
Query OK, 0 rows affected (0.31 sec)
2.脚本循环插入数据
[root@db03 ~]# vim insert.sh
#/bin/bash
while true;do
mysql -e "use test;insert into linux9(name) values('lhd')"
sleep 1
done
[root@db03 ~]# sh insert.sh
3.停掉一台机器的IO线程
#此时db03是主库,停掉db01的IO线程
mysql> stop slave io_thread;
4.停掉db03的主库
[root@db03 ~]# systemctl stop mysqld
5.查看主库切换
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.16.1.52
Master_User: rep
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000008
Read_Master_Log_Pos: 67437
Relay_Log_File: db01-relay-bin.000002
Relay_Log_Pos: 14904
Relay_Master_Log_File: mysql-bin.000008
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
标签:主库,Slave,mysql,MHA,Master,切换,172.16,db03 来源: https://www.cnblogs.com/Applogize/p/13393815.html