mysql主备切换[高可用]

到这一步的时候, 是主备部署已经处理好, 请关注:mysql主备部署[高可用]

这次使用的是keepalived-1.2.22.tar.gz版, 官网地址:keeplived官网

笼统知识请自行查询百度下面开始步骤

第一步:安装keepalived-1.2.22

解压
tar -zxvf keepalived-1.2.22.tar.gz

编译
cd keepalived-1.2.22
./configure --prefix=/usr/local/keepalived/(新建文件夹喔)
安装
make && make install

服务脚本
cp /usr/local/etc/rc.d/init.d/keepalived  /etc/init.d/keepalived
配置文件
cp /usr/local/keepalived/etc/keepalived.conf /etc/keepalived/keepalived.conf
服务
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/keepalived

加入服务
chkconfig --add keepalived
chkconfig keepalived on

service keepalived start   #启动服务
service keepalived stop    #停止服务
service keepalived restart #重启服务

上面的额操作主备机器都需要安装

第二步:配置文件

master:keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id HA_MySQL
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    nopreempt
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.88.88
    }
}

virtual_server 192.168.88.88 3306 {
    delay_loop 2
    lb_algo wrr
    lb_kind DR
    persistence_timeout 60
    protocol TCP
    real_server 192.168.75.61 3306 {
        weight 3
        notify_down /etc/keepalived/down.sh
        TCP_CHECK {
            connect_timeout 10
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
}

slave:keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id HA_MySQL
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 90
    advert_int 1
    nopreempt
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.88.88
    }
}

virtual_server 192.168.88.88 3306 {
    delay_loop 2
    lb_algo wrr
    lb_kind DR
    persistence_timeout 60
    protocol TCP
    real_server 192.168.75.62 3306 {
        weight 3
#        echo"62....1"
        notify_down /etc/keepalived/down.sh
#        notify_up /etc/keepalived/up.sh
#        echo"62....2"
        TCP_CHECK {
            connect_timeout 10
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
}

down:down.sh

#!/bin/bash
pkill keepalived

第三步:测试

主:192.168.75.61
备:192.168.75.62

主:
[root@qwzs08 log]#service mysqld start
[root@qwzs08 log]#service keeplived start

保证已经启动成功!
[root@qwzs08 log]#ip addr

会显示出下面的vip(我上面配置文件把master放在61)

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 mq state UNKNOWN qlen 1000
    link/ether 00:50:56:89:a3:28 brd ff:ff:ff:ff:ff:ff
    inet 192.168.75.61/24 brd 192.168.75.255 scope global eth0
    inet 192.168.88.88/32 scope global eth0
    inet6 fe80::250:56ff:fe89:a328/64 scope link 
       valid_lft forever preferred_lft forever

表示vip正常

此时在备机
[root@qwzs07 log]#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 mq state UNKNOWN qlen 1000
    link/ether 00:50:56:89:cb:a6 brd ff:ff:ff:ff:ff:ff
    inet 192.168.75.62/24 brd 192.168.75.255 scope global eth0
    inet6 fe80::250:56ff:fe89:cba6/64 scope link 
       valid_lft forever preferred_lft forever


是没有vip的, 恭喜您!配置成功!

第四步:漂移

模拟主机宕机
ps aux | grep mysqld

root      1176  0.0  0.0  11336  1408 ?        S    15:38   0:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --datadir=/usr/local/mysql/data --pid-file=/usr/local/mysql/data/mysql3306.pid
mysql     1591  7.1  1.8 2736136 597708 ?      Sl   15:38   3:19 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/usr/local/mysql/data/mysql3306.err --pid-file=/usr/local/mysql/data/mysql3306.pid
root      1978  0.0  0.0 103248   844 pts/0    S+   16:24   0:00 grep mysql

kill -9 1176 1591

此时,主机的mysql挂掉了,您怎么确定是有没有漂移呢?
查一下vip
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 mq state UNKNOWN qlen 1000
    link/ether 00:50:56:89:cb:a6 brd ff:ff:ff:ff:ff:ff
    inet 192.168.75.61/24 brd 192.168.75.255 scope global eth0
    inet6 fe80::250:56ff:fe89:cba6/64 scope link 
       valid_lft forever preferred_lft forever

已经没有了
再去备机查一下vip
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 mq state UNKNOWN qlen 1000
    link/ether 00:50:56:89:a3:28 brd ff:ff:ff:ff:ff:ff
    inet 192.168.75.62/24 brd 192.168.75.255 scope global eth0
    inet 192.168.88.88/32 scope global eth0
    inet6 fe80::250:56ff:fe89:a328/64 scope link 
       valid_lft forever preferred_lft forever

look, 漂过来了

现在切换到主机把的mysql和keeplived开启

此时主机的服务已经开起来了, 但是vip并没有漂过去, 这就是nopreempt的作用, 防止脑裂

这时候加入备机slave挂掉, vip就会漂移到主机master, 实现高可用主从切换

此时如果能实现漂移就是成功了, 下面是我遇到的问题

1.keepalived执行后日志狂刷, 2.脚本并没有执行(down.sh),具体情况就是mysql挂掉后,keeplived并没有自杀,导致vip漂移失败, 但是手动关闭keeplived后会实现漂移, 原因就在于down脚本没有得到执行。

日志报错:

Nov 21 16:05:27 qwzs08 abrt[13378]: Not saving repeating crash in '/usr/sbin/keepalived'
Nov 21 16:05:27 qwzs08 Keepalived_healthcheckers: IPVS: Can't initialize ipvs: Protocol not available
Nov 21 16:05:27 qwzs08 Keepalived_healthcheckers: Netlink reflector reports IP 192.168.75.62 added
Nov 21 16:05:27 qwzs08 Keepalived_healthcheckers: Netlink reflector reports IP 192.168.75.62 added
Nov 21 16:05:27 qwzs08 Keepalived_healthcheckers: Registering Kernel netlink reflector
Nov 21 16:05:27 qwzs08 Keepalived_healthcheckers: Registering Kernel netlink command channel
Nov 21 16:05:27 qwzs08 Keepalived_healthcheckers: Opening file '/etc/keepalived/keepalived.conf'.
Nov 21 16:05:27 qwzs08 Keepalived_healthcheckers: Configuration is using : 9635 Bytes

很纠结,经过排查,原因是ip_vs模块系统默认没有自动加载

执行命令:

查看
lsmod | grep ip_vs 
(如果没有任何输出则表示ip_vs模块并没有被内核加载)

手动加载
modprobe ip_vs

modprobe ip_vs_wrr

然后再看日志已经恢复正常

此时再查看ip_vs

lsmod | grep ip_vs 

ip_vs_wrr               2179  1 
ip_vs                 115643  3 ip_vs_wrr
libcrc32c               1246  1 ip_vs
ipv6                  321422  68 ip_vs,ip6t_REJECT,nf_conntrack_ipv6,nf_defrag_ipv6

ok!