keepalive配置mysql自动故障转移
本文先配置了一个双master环境,互为主从,然后通过Keepalive配置了一个虚拟IP,客户端通过虚拟IP连接master1,当master1宕机,自动切换到master2。一次只能连接其中一个master进行读写,所以是active-passive模式。
一 Mysql主主复制搭建
1.1 实验环境
两台机器事先都已经装好了mysql单实例。
二者的端口号需要保持一致,否则在最后用vip连接的时候,不能使用相同端口号连接。
1.2 实验步骤
1.2.1 修改配置文件
修改master1:
在[mysqld]下面添加:
server-id = 1
relay-log=/data/server/mysql_3307/binlog/ZabbixServer-relay-bin
relay-log-index=/data/server/mysql_3307/binlog/ZabbixServer-relay-bin.index
auto-increment-offset = 1
auto-increment-increment = 2
log-slave-updates=true
修改master2:
在[mysqld]下面添加:
server-id = 3
relay-log =/data/server/mysql/binlog/single-relay-bin
relay-log-index=/data/server/mysql/binlog/single-relay-bin.index
auto-increment-offset = 2
auto-increment-increment = 2
log-slave-updates=true
添加auto-increment-offset那两项,是为了避免在MySQL INSERT时主键冲突。
修改完后记得重启mysql
1.2.2 建复制用户
分别在两台mysql上执行
GRANT REPLICATION SLAVE ON *.* TO 'RepUser'@'%'identified by 'beijing';
1.2.3 指向master
两台服务器均为新建立,且无其它写入操作,各服务器只需记录当前自己二进制日志文件及事件位置,以之作为另外的服务器复制起始位置即可。否则,需要先备份主库,在备库进行恢复,从而保持数据一致,然后再指向master。
Master1:
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 302| | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
Master2:
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 120 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
#Master1指向Master2
- CHANGE MASTER TO MASTER_USER='RepUser',MASTER_HOST='192.168.1.21',MASTER_PASSWORD='beijing',MASTER_PORT=3307,MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=120;
#Master2指向Master1
- CHANGE MASTER TO MASTER_USER='RepUser',MASTER_HOST='192.168.1.22',MASTER_PASSWORD='beijing', MASTER_PORT=3307,MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=302;
1.2.4 分别启动slave
start slave ;
确保show slave status
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
测试两边是否同步,略。
二:配置keepalived
1 keepalive安装
分别在master1,master2上安装keepalive
- yum install -y popt-devel
- cd /usr/local/src
- wget http://www.keepalived.org/software/keepalived-1.2.2.tar.gz
- tar zxvf keepalived-1.2.2.tar.gz
- cd keepalived-1.2.2
- ./configure --prefix=/
- make
- make install
#假如在执行./configure --prefix=/时报错: OpenSSL is not properly installed on your system !!!Can notinclude OpenSSL headers files,则yum install openssl-devel -y
2 分别在master1,master2上新建检查mysql脚本
vi /root/check_mysql.sh
内容如下
chmod +x /root/check_mysql.sh
3 修改配置文件
vi /etc/keepalived/keepalived.conf
master1和master2配置文件内容相同。
内容:
这里state不配置MASTER,且优先级一样,是期望在MASTER1宕机后再恢复时,不主动将MASTER状态抢过来,避免MySQL服务的波动。
由于不存在使用lvs进行负载均衡,不需要配置虚拟服务器virtual server,下同。
4 vi /etc/sysconfig/iptables
#注意,在两台机器上都要修改。
添加:
-A INPUT -d 192.168.1.60/32 -j ACCEPT
-A INPUT -d 224.0.0.18 -j ACCEPT #添加VRRP通讯支持
注意:第一行中的192.168.1.60需要改成你自己的vip。
service iptables restart
5 启动keepalived
在master1、master2上分别启动:
service keepalived start
分别执行ip addr命令,可以在其中一台机器上看到虚拟IP.如:
[root@slave1 keepalived]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_faststate UP qlen 1000
link/ether 08:00:27:04:05:16 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.22/24 brd 192.168.1.255 scope global eth0
inet 192.168.1.60/32 scope global eth0
inet6 fe80::a00:27ff:fe04:516/64 scope link tentativedadfailed
valid_lft forever preferred_lft forever
说明虚拟vip连在了master1这台机器上。
如果自动只连接到了master2,关闭master2的keepalived,再启动,自动就连接到master1了。
现在都可以ping通虚拟ip了。
6 测试
停止master1服务器keepalived,检查VIP是否切换到master2服务器(用ip addr命令验证即可);
三 测试高可用环境是否配置成功
3.1 建允许远程访问的用户
在master1,master2创建允许远程访问的用户:
grant select,update,delete,insert on *.* to 'dandan' identified by 'dandan';
3.2 访问虚拟IP
用一台同网段的机器访问通过vip访问数据库:
mysql -u dandan-pdandan -h 192.168.1.60 --port 3307
停止master1服务器的mysql,VIP切换到了master2服务器。
在master2上查看:
- mysql> showprocesslist;
- +----+-------------+--------------------+------+---------+------+-----------------------------------------------------------------------------+------------------+
- | Id | User | Host | db | Command | Time | State | Info |
- +----+-------------+--------------------+------+---------+------+-----------------------------------------------------------------------------+------------------+
- | 3 | root | localhost | dba | Query | 0 | init | show processlist |
- | 14 | systemuser | | NULL |Connect | 247 | Reconnecting after afailed master event read | NULL |
- | 15 | systemuser | | NULL |Connect | 207 | Slave has read all relaylog; waiting for the slave I/O thread to update it | NULL |
- | 90 |dandan | 192.168.1.60:39995 |dba | Sleep | 8| | NULL |
- +----+-------------+--------------------+------+---------+------+-----------------------------------------------------------------------------+------------------+
看到了dandan的连接信息。