Keepalived+Lvs+Mysql主主复制_MySQL

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