准备
1 1. 双主 master1 192.168.199.49
2 master2 192.168.199.50
3 VIP 192.168.199.52 //虚拟IP
4 2.环境 master:nginx + php + mysql + keepalived
5 VIP:只要和master在一个局域网内即可。
6 3. 服务器之间网络通畅，可以互相ping通。
7 4. 2个服务器的mysql版本要一致。数据库密码一致
8 5. 防火墙增加允许组播和允许VRRP（虚拟路由器冗余协）通信，这样主服务器在故障恢复后才能抢回资源
9 -A INPUT -s 182.148.15.0/24 -d 224.0.0.18 -j ACCEPT
10 -A INPUT -s 182.148.15.0/24 -p vrrp -j ACCEPT
11 重启生效：service iptables reload
配置服务器
1 服务器1：
2
3 在my.cnf文件的[mysqld]配置区域添加下面内容：
4 log-bin=mysql-bin #记录二进制文件
5 binlog_format=mixed #mysql默认采用的二进制格式
6 server-id = 2 #服务号，必须是唯一的，一般取IP的后8位
7 expire_logs_days = 10 #binlog过期清理时间
8
9 binlog-do-db = db1 #需要服务的数据库。
10 #replicate-ignore-db = db3,mysql,test,information_schema,performance_schema,transfer_new #不需要复制的数据库
11 #replicate-wild-ignore-table=garbage.% #有问题可以尝试使用此项配置
12 sync_binlog = 1 #表示binlog日志在每1次写入后与硬盘同步，设置1最安全也最慢
13 auto-increment-increment = 2 #服务器个数
14 auto-increment-offset = 2 #自增偏移量，如果有2台，则一台设置1，另一台设置2
15 slave-skip-errors = all #从库复制时跳过所有的错误
16 服务器2：
17
18 log-bin=mysql-bin
19 binlog_format=mixed
20 server-id = 1
21 expire_logs_days = 10
22 binlog-do-db = db1
23 #replicate-ignore-db = db3,mysql,test,information_schema,performance_schema,transfer_new
24 #replicate-wild-ignore-table=garbage.% #有问题可以尝试使用此项配置
25 sync_binlog = 1
26 auto-increment-increment = 2
27 auto-increment-offset = 1
28 slave-skip-errors = all
2台服务器都重启mysql服务：
1 service mysql restart
同步配置(2台服务器分别执行)
1 给对方授权复制权限
2
3 //对方服务器60.205.182.26允许复制本服务器数据库，用户名repl 密码ocnt-123
4 mysql> grant replication slave,replication client on *.* to repl@'60.205.182.26' identified by "ocnt-123";
5 //生效
6 mysql> flush privileges;
7 //锁定表
8 mysql> flush tables with read lock;
同步数据
1 1.锁定表
2 mysql> flush tables with read lock;
3 2.同步数据，可使用navicat
同步操作(2台服务器分别执行)
1 //查看各自服务器当前二进制日志文件名称和记录位置
2 mysql> show master status;
3
4 <!-----------------------服务器1同步------------------------------------>
5 //解锁表
6 mysql> unlock tables;
7 //停止slave
8 mysql> slave stop;
9 //开始同步: IP、用户名和密码为服务器2刚才grant授权配置的,日志文件和pos值得位置通过服务器2 show master status查看得来
10 mysql> change master to master_host='101.200.63.35',master_user='repl',master_password='123456',master_log_file='mysql-bin.000016',master_log_pos=363;
11 //开启slave
12 mysql> start slave;
13
14 <!-----------------------服务器2同步------------------------------------>
15 //解锁表
16 mysql> unlock tables;
17 //停止slave
18 mysql> slave stop；
19 <!--开始同步-->
20 change master to master_host='60.205.182.26',master_user='repl',master_password='123456',master_log_file='mysql-bin.000028',master_log_pos=107;
21 <!--开启slave-->
22 mysql> start slave;
查看同步状态，如下出现两个“Yes”，表明同步成功！（Slave_IO_Running和Slave_SQL_Running）
1 mysql> show slave status \G;
配置到此处就完成了双主热备。
keepalived故障自动切换配置
1 master1:192.168.199.49 主机1
2 master2:192.168.199.50 主机2 备份
3 VIP:192.168.199.52 虚拟IP
4 ### 2台服务器安装keepalived
5
6 [root@localhost ]#yum install -y openssl-devel
7 [root@localhost src]#cd /usr/local/src/
8 [root@localhost src]# wget http://www.keepalived.org/software/keepalived-1.3.5.tar.gz
9 [root@localhost src]# tar -zvxf keepalived-1.3.5.tar.gz
10 [root@localhost src]# cd keepalived-1.3.5
11 [root@localhost keepalived-1.3.5]# ./configure --prefix=/usr/local/keepalived
12 [root@localhost keepalived-1.3.5]# make && make install
13
14 [root@localhost keepalived-1.3.5]# cp /usr/local/src/keepalived-1.3.5/keepalived/etc/init.d/keepalived /etc/rc.d/init.d/
15 [root@localhost keepalived-1.3.5]# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
16 [root@localhost keepalived-1.3.5]# mkdir /etc/keepalived/
17 [root@localhost keepalived-1.3.5]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
18 [root@localhost keepalived-1.3.5]# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
19 [root@localhost keepalived-1.3.5]# echo "/etc/init.d/keepalived start" >> /etc/rc.local
master1服务器配置
1 [root@master1 ~]# cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
2 [root@master1 ~]# vim /etc/keepalived/keepalived.conf ＃删除所有内容，重新配置如下
3
4 ! Configuration File for keepalived
5 global_defs {
6 notification_email {
7 412140451@qq.com
8 }
9
10 notification_email_from 412140451@qq.com
11 smtp_server 127.0.0.1
12 smtp_connect_timeout 30
13 router_id MASTER-HA
14 }
15
16 vrrp_script chk_mysql_port { #检测mysql服务是否在运行
17 script "/opt/chk_mysql.sh" #这里通过脚本监测
18 interval 3 #脚本执行间隔，每3s检测一次
19 weight -5 #脚本结果导致的优先级变更，检测失败（脚本返回非0）则优先级 -5
20 fall 2 #检测连续2次失败才算确定是真失败。会用weight减少优先级（1-255之间）
21 rise 1 #检测1次成功就算成功。但不修改优先级
22 }
23
24 vrrp_instance VI_1 {
25 state MASTER
26 interface eth0 #指定虚拟ip的网卡接口
27 mcast_src_ip 192.168.199.49 #本机master的 IP地址
28 virtual_router_id 100 #路由器标识，MASTER和BACKUP必须是一致的
29 priority 100 #定义优先级，数字越大，优先级越高，在同一个vrrp_instance下，MASTER的优先级必须大于BACKUP的优先级。这样MASTER故障恢复后，就可以将VIP资源再次抢回来
30 advert_int 1
31 authentication { #加密协议
32 auth_type PASS
33 auth_pass 1111
34 }
35 virtual_ipaddress {
36 192.168.199.52 #虚拟IP地址 VIP
37 }
38
39 track_script {
40 chk_mysql_port
41 }
42 }
master2服务器配置 修改 mcast_src_ip priority
1 global_defs {
2 notification_email {
3 412140451@qq.com
4 }
5
6 notification_email_from 412140451@qq.com
7 smtp_server 127.0.0.1
8 smtp_connect_timeout 30
9 router_id MASTER-HA
10 }
11
12 vrrp_script chk_mysql_port {
13 script "/opt/chk_mysql.sh"
14 interval 3
15 weight -5
16 fall 2
17 rise 1
18 }
19
20 vrrp_instance VI_1 {
21 state BACKUP
22 interface eth0
23 mcast_src_ip 192.168.199.50
24 virtual_router_id 100
25 priority 90
26 advert_int 1
27 authentication {
28 auth_type PASS
29 auth_pass 1111
30 }
31 virtual_ipaddress {
32 192.168.199.52
33 }
34
35 track_script {
36 chk_mysql_port
37 }
38 }
2个服务器都编写检测切换mysql脚本
1 KeepAlived做心跳检测，如果Master的MySQL服务挂了(3306端口挂了),那么它就会选择自杀。Slave的KeepAlived通过心跳检测发现这个情况，就会将VIP的请求接管
2 vim /opt/chk_mysql.sh
3
4 #!/bin/bash
5 CHECK_TIME=3
6
7 #Mysql
8 host='localhost'
9 port='3306'
10 user='root'
11 password='ocnt-123'
12 mysqlclient="mysql"
13
14 #mysql is working MYSQL_OK is 1 , mysql down MYSQL_OK is 0
15 function check_mysql_helth (){
16 #NEW=$MYSQL -h $MYSQL_HOST -u $MYSQL_USER -p${MYSQL_PASSWORD} -e "show status;" >/dev/null 2>&1
17 $mysqlclient --host=$host --port=$port --user=$user --password=$password -e "show databases;" > /dev/null 2>&1
18
19 if [ $? == 0 ]
20 then
21 MYSQL_OK=1
22 else
23 MYSQL_OK=0
24 fi
25 # echo $MYSQL_OK
26 return $MYSQL_OK
27 }
28
29 while [ $CHECK_TIME -ne 0 ]
30 do
31 let "CHECK_TIME -= 1"
32 check_mysql_helth
33 if [ $MYSQL_OK == 1 ] ; then
34 CHECK_TIME=0
35 exit 0
36 fi
37 if [ $MYSQL_OK -eq 0 ] && [ $CHECK_TIME -eq 0 ]
38 then
39 pkill keepalived
40 exit 1
41 fi
42 sleep 1
43 done
赋权限
1 chmod 755 /opt/chk_mysql.sh
启动服务
1 关闭防火墙
2 service iptables stop
3 启动服务
4 /etc/init.d/keepalived start
数据库测试
1 使用局域网内的客户端连接VIP
2 mysql -h192.168.199.52 -uroot -pocnt-123
3 测试是否可用
故障切换检测
1 默认情况下，vip是在master1上的。使用"ip addr"命令查看vip切换情况
2 ip addr
3 查找
4 inet 192.168.199.49/32 scope global eth0 //这个32位子网掩码的vip地址表示该资源目前还在master1机器上，而master2机器上没有
5 同时查看 tail -f /var/log/message 会发现
6 Dec 13 17:52:38 localhost Keepalived_vrrp[65545]: VRRP_Instance(VI_1) Entering MASTER STATE
7 Dec 13 17:52:38 localhost Keepalived_vrrp[65545]: VRRP_Instance(VI_1) setting protocol VIPs.
8 Dec 13 17:52:38 localhost Keepalived_vrrp[65545]: Sending gratuitous ARP on eth0 for 192.168.199.51
9
10 关掉master1的mysql服务
11 service mysql stop
12 查看 master1的日志 tail -f /var/log/message 会发现
13 Dec 13 18:52:44 localhost Keepalived_vrrp[65545]: Stopped
14 Dec 13 18:52:44 localhost Keepalived[65542]: Stopped Keepalived v1.3.5 (03/19,2017), git commit v1.3.5-6-g6fa32f2
15
16 查看master2的日志
17 Dec 13 18:52:45 localhost Keepalived_vrrp[28451]: VRRP_Instance(VI_1) Transition to MASTER STATE
18 Dec 13 18:52:46 localhost Keepalived_vrrp[28451]: VRRP_Instance(VI_1) Entering MASTER STATE
19 Dec 13 18:52:46 localhost Keepalived_vrrp[28451]: VRRP_Instance(VI_1) setting protocol VIPs.
20 Dec 13 18:52:46 localhost Keepalived_vrrp[28451]: Sending gratuitous ARP on eth0 for 192.168.199.51
21
22 此时就已经转移到master2上，
23 恢复master1 的mysql服务
24 service mysql start
25 恢复master1 的keepalive
26 /etc/init.d/keepalived start
27
28 查看master1的日志
29 Dec 13 18:54:41 localhost Keepalived_vrrp[71002]: VRRP_Instance(VI_1) Transition to MASTER STATE
30 Dec 13 18:54:42 localhost Keepalived_vrrp[71002]: VRRP_Instance(VI_1) Entering MASTER STATE
31 Dec 13 18:54:42 localhost Keepalived_vrrp[71002]: VRRP_Instance(VI_1) setting protocol VIPs.
32 Dec 13 18:54:42 localhost Keepalived_vrrp[71002]: Sending gratuitous ARP on eth0 for 192.168.199.51
33
34 查看master2的日志
35 Dec 13 18:54:41 localhost Keepalived_vrrp[28451]: VRRP_Instance(VI_1) Received advert with higher priority 100, ours 90
36 Dec 13 18:54:41 localhost Keepalived_vrrp[28451]: VRRP_Instance(VI_1) Entering BACKUP STATE
37 Dec 13 18:54:41 localhost Keepalived_vrrp[28451]: VRRP_Instance(VI_1) removing protocol VIPs.
38
39 说明服务已经转移到master2上了。
40 至此完成
完成
其它：删除主从复制
1 mysql> stop slave;
2 mysql> slave reset;
3 mysql> reset master;
keepalived
1 启动
2 /etc/init.d/keepalived start
异常解决办法
1 如果不能正常复制，查看状态
2 sql> show slave status \G;
3 然后可以看到错误信息，一般情况下，重启一下slave就好了
4 sql> stop slave;