时间:2021-07-01 10:21:17 帮助过:40人阅读
一简介
Keepalived+lvs+mysql主主复制是比较常用的一种Mysql高可用方案,其中lvs 提供读负载均衡,Keepalived通过虚拟vip漂移实现故障自动转移,而Mysql虽然配置成主主复制,但是一般都是采用单点写入来保证数据一致性。
整个方案实现非常简单,仅需两台服务器即可,安装配置也相对简单,但需要自己写脚本实现keepalived服务的开启和关闭,适用于只有两台数据库服务器并且未实现读写分离的场景。系统整体结构框图如下
二环境搭建
2.1 环境配置如下
Keepalived Server |
LVS Server |
LVS Realserver |
MySQL Master-Master |
Write VIP |
Read VIP |
OS |
MySQL |
Master 10.0.11.243 |
10.0.11.243 |
10.0.11.243 |
10.0.11.243 |
10.0.11.190 |
10.0.11.191 |
Centos6 |
Percona5.6 |
Backup 10.0.11.244 |
10.0.11.244 |
10.0.11.244 |
10.0.11.244 |
10.0.11.190 |
10.0.11.191 |
Centos6 |
Percona5.6 |
2.2 mysql master-master复制配置
主主复制配置本质上就是配置两台服务器互相的主从,实现比较简单,大致步骤如下
2.2.1 在Master上创建一个复制账户
mysql>grantreplication slave on *.* to rep71@10.0.11.244identified by‘123456’;
mysql>flushprivileges;
2.2.2 修改两台mysql配置文件my.cnf如下
##Replication General Config (both master and slave) server-id= 101 log-bin= mysql-log-bin auto-increment-increment= 2 auto-increment-offset= 1 binlog_format= row relay_log= mysql-relay-bin
2.2.3 在Master服务器上执行show master status,记录下File和Position
mysql>show master status\G; ***************************1. row *************************** File:mysql-log-bin.000005 Position:327933 Binlog_Do_DB: Binlog_Ignore_DB:test,mysql,information_schema,performance_schema
2.2.4 在Slave服务上执行
mysql> slave stop; Query OK, 0 rows affected, 1 warning (0.00 sec) mysql> change master to -> master_host='10.0.11.243', -> master_user='rep71', -> master_password='123456', -> master_log_file=' mysql-log-bin.000005', -> master_log_pos=327933; Query OK, 0 rows affected (0.01 sec) mysql> start slave;
2.2.5重复以上四个步骤,在Slave服务器上创建账户rep72,show master status,在Master上start slave,这样mysql的主主同步就配置好了,分别在两台服务器上运行show slave status,如果结果都显示Slave_IO_Running: Yes,Slave_SQL_Running: Yes,则证明同步正常。
2.3 Keepalived的安装
2.3.1 在 master、backup 服务器都进行安装:
wget http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz sudotar zxvf ipvsadm-1.24.tar.gz cdipvsadm-1.24 sudoln -s /usr/src/kernels/2.6.32-358.el6.x86_64/ /usr/src/linux make sudomake install
2.4 Keepalived 的安装
2.4.1在 master、backup 服务器都进行安装:
wget http://www.keepalived.org/software/keepalived-1.1.19.tar.gz tarzxvf keepalived-1.1.19.tar.gz cdkeepalived-1.1.19 yuminstall -y openssl openssl-devel sudoyum install popt-devel –y ./configure--sysconf=/etc/ --with-kernel-dir=/usr/src/kernels/2.6.18-308.el5-x86_64/ make sudomake install ln -s /usr/local/sbin/keepalived /sbin/
2.4.2 Master上的Keepalived 的配置
global_defs{ router_id mysqlmha1 } vrrp_scriptcheck_run { script"/etc/keepalived/check_mysqll.sh" interval 1 } vrrp_instanceVI_1 { state MASTER interface em1 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } track_script { check_run } virtual_ipaddress { 10.0.11.190 dev em1 label em1:1 10.0.11.191 dev em1 label em1:2 } } virtual_server10.0.11.190 3306 { delay_loop6 lb_algorr lb_kindDR persistence_timeout20 protocolTCP sorry_server10.0.11.244 3306 real_server10.0.11.243 3306 { weight3 TCP_CHECK{ connect_timeout3 nb_get_retry3 delay_before_retry3 connect_port3306 } } } virtual_server10.0.11.191 3306 { delay_loop6 lb_algorr lb_kindDR #persistence_timeout20 protocolTCP real_server10.0.11.243 3306 { weight3 TCP_CHECK{ connect_timeout3 nb_get_retry3 delay_before_retry3 connect_port3306 } } real_server10.0.11.244 3306 { weight3 TCP_CHECK{ connect_timeout3 nb_get_retry3 delay_before_retry3 connect_port3306 } } }
2.4.3 Backup 的 keepalived 的配置
global_defs { router_id mysqlmha1 } vrrp_script check_run { script "/etc/keepalived/check_mysqll.sh" interval 1 } vrrp_instance VI_1 { state BACKUP interface em1 virtual_router_id 51 priority 90 advert_int 1 authentication { auth_type PASS auth_pass 1111 } track_script { check_run } virtual_ipaddress { 10.0.11.190 dev em1 label em1:1 10.0.11.191 dev em1 label em1:2 } } virtual_server 10.0.11.190 3306 { delay_loop 6 lb_algo rr lb_kind DR persistence_timeout 20 protocol TCP sorry_server 10.0.11.244 3306 real_server 10.0.11.243 3306 { weight 3 TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3 connect_port 3306 } } } virtual_server 10.0.11.191 3306 { delay_loop 6 lb_algo rr lb_kind DR #persistence_timeout 20 protocol TCP real_server 10.0.11.243 3306 { weight 3 TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3 connect_port 3306 } } real_server 10.0.11.244 3306 { weight 3 TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3 connect_port 3306 } } }
2.5 Master 和 backup 的 realserver 的配置
对于 realserver 的配置 master 和 backup 是一致的,脚本内容如下:
#!/bin/bash #description: Config realserver lo and apply noarp SNS_VIP=10.1.11.190 SNS_VIP2=10.0.11.191 /etc/rc.d/init.d/functions case"$1" in start) ifconfiglo:0 $SNS_VIP netmask 255.255.255.255 broadcast $SNS_VIP ifconfiglo:1 $SNS_VIP2 netmask 255.255.255.255 broadcast $SNS_VIP2 /sbin/routeadd -host $SNS_VIP dev lo:0 /sbin/routeadd -host $SNS_VIP2 dev lo:1 echo"1" >/proc/sys/net/ipv4/conf/lo/arp_ignore echo"2" >/proc/sys/net/ipv4/conf/lo/arp_announce echo"1" >/proc/sys/net/ipv4/conf/all/arp_ignore echo"2" >/proc/sys/net/ipv4/conf/all/arp_announce echo"1" >/proc/sys/net/ipv4/conf/em1/arp_ignore echo"2" >/proc/sys/net/ipv4/conf/em1/arp_announce sysctl-p >/dev/null 2>&1 echo"RealServer Start OK" ;; stop) ifconfiglo:0 down ifconfiglo:1 down routedel $SNS_VIP >/dev/null 2>&1 routedel $SNS_VIP2 >/dev/null 2>&1 echo"0" >/proc/sys/net/ipv4/conf/lo/arp_ignore echo"0" >/proc/sys/net/ipv4/conf/lo/arp_announce echo"0" >/proc/sys/net/ipv4/conf/all/arp_ignore echo"0" >/proc/sys/net/ipv4/conf/all/arp_announce echo"0" >/proc/sys/net/ipv4/conf/em1/arp_ignore echo"0" >/proc/sys/net/ipv4/conf/em1/arp_announce echo"RealServer Stoped" ;; *) echo"Usage: ___FCKpd___7 {start|stop}" exit1 esac exit0
2.6 编辑脚本控制Keepalived的开启和停止
大体意思是只要检测到mysql服务停止keepalived服务也停止 ,因为keepalived是通过组播方式告诉本网段自己还活着当mysql服务停止后keepalived还依然运行 这时就需要停止keepalived让另一个主机获得虚拟IP,可以在后台运行这个脚本 也可以在keepalived配置文件加入这个脚本,master和slave节点都需要,只是数据库用户名和密码有区别
[root@244 ~]#more /etc/keepalived/check_mysql.sh #20140722 #!/bin/bash MYSQL=/usr/bin/mysql MYSQL_HOST=10.0.11.243 MYSQL_USER=root MYSQL_PASSWORD=mysql CHECK_TIME=3 #mysql isworking MYSQL_OK is 1 , mysql down MYSQL_OK is 0 MYSQL_OK=1 function check_mysql_helth (){ $MYSQL -h $MYSQL_HOST -u $MYSQL_USER -p$MYSQL_PASSWORD -e "showstatus;" >/dev/null 2>&1 if [ $? = 0 ] ;then MYSQL_OK=1 else MYSQL_OK=0 fi return $MYSQL_OK } while [ $CHECK_TIME -ne 0 ] do let "CHECK_TIME -= 1" check_mysql_helth if [ $MYSQL_OK = 1 ] ; then CHECK_TIME=0 exit 0 fi if [ $MYSQL_OK -eq 0 ] && [ $CHECK_TIME -eq 0 ] then pkill keepalived exit 1 fi sleep 1 done
该脚本需要有执行权限,通过以下命令加上执行权限
# chmod +x check_mysql.sh
2.7 测试Keepalived自动故障转移
Master和slave上执行sudo servicekeepalived start,在master上执行ip a
Slave上执行 ip a
从上可以看到masteMySQL上虚拟IP绑定成功,backup MySQL上keepalived服务正常运行,但无虚拟IP(这属于正常)
客户端能通过vip连接上mysql
停止master上的mysql服务,可发现Keepalived服务也会停止
这时候slave运行ip a发现绑定了虚拟ip,并且从库mysql运行正常,而客户端依旧能通过vip连上数据库
重启master的mysql和Keepalived以后,并在slave库运行start slave,master运行ip a发现恢复之前的服务
2.8 测试lvs的负载均衡效果
启动 master 和 backup 的 mysql 以后,再在 master 和 backup 执行如下命令启
动 keepalived 和 realserver 脚本:
/etc/rc.d/init.d/realserver.sh start
/etc/rc.d/init.d/keepalived start
运行master和backup上的sudo ipvsadm -ln可看到如下信息
在客户端通过read vip连接到mysql并执行几次select,可考到inaction发生了变化,证明实现了负载均衡