配置 MySQL 负载均衡 高可用
架构
MySQL:
master 192.168.131.9
slave-1 192.168.131.10
slave-2 192.168.131.11
LB:
MASTER 192.168.131.161
BACKUP 192.168.131.159
VIP:
192.168.131.16
LVS
yum install ipvsadm -y
利用 arp 协议, 搭建路由网桥连接
从而得到流量分发的目的
LVS 配置
配置 keepalived 时, LVS 会自动得到配置, 无需手动
keepalived
[root@lvs ~]# yum install ipvsadm -y
[root@lvs ~]# ifconfig lo:0 192.168.131.16/32
[root@lvs ~]# yum install keepalived -y
[root@lvs ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id lvs-keepalived-master #辅助改为lvs-backup
}
vrrp_instance VI_1 {
state MASTER
interface ens33 #VIP绑定接口
virtual_router_id 51 #VRID 同一组集群，主备一致
priority 100 #本节点优先级，辅助改为50
advert_int 1 #检查间隔，默认为1s
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.131.16
}
}
virtual_server 192.168.131.16 3306 { #LVS配置
delay_loop 3
lb_algo rr #LVS调度算法
lb_kind DR #LVS集群模式（路由模式）
protocol TCP #健康检查使用的协议
real_server 192.168.131.9 3306 {
weight 1
inhibit_on_failure #当该节点失败时，把权重设置为0，而不是从IPVS中删除
TCP_CHECK { #健康检查
connect_port 3306 #检查的端口
connect_timeout 3 #连接超时的时间
}
}
real_server 192.168.131.10 3306 {
weight 1
inhibit_on_failure
TCP_CHECK {
connect_timeout 3
connect_port 3306
}
}
real_server 192.168.131.11 3306 {
weight 1
inhibit_on_failure
TCP_CHECK {
connect_timeout 3
connect_port 3306
}
}
}
[root@lvs ~]# scp /etc/keepalived/keepalived.conf 192.168.131.159:/etc/keepalivce/
# 注意:
keepalived文件拷贝到 BACKUP 节点后, 要修改配置文件中的
state 参数
priority 参数
不然会有极大的可能从而产生脑裂
启动,并观测结果
[root@lvs ~]# systemctl start keepalived
[root@lvs ~]# systemctl enable keepalived
[root@backup ~]# systemctl start keepalived
[root@backup ~]# systemctl enable keepalived
[root@lvs ~]# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.131.16:mysql rr
-> 192.168.131.9:mysql Route 1 0 0
-> 192.168.131.10:mysql Route 1 0 0
-> 192.168.131.11:mysql Route 1 0 0
[root@backup ~]# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP backup:mysql rr
-> 192.168.131.9:mysql Route 1 0 0
-> 192.168.131.10:mysql Route 1 0 0
-> 192.168.131.11:mysql Route 1 0 0
数据库状态检测脚本
版本一：简单使用：
#!/bin/bash
/usr/bin/mysql -h ip -uroot -p123 -e "show status;" &>/dev/null
if [ $? -ne 0 ] ;then
systemctl stop keepalived
fi
# 此处的ip是本地ip
版本二：检查多次
# vim /root/keepalived_check_mysql.sh
#!/bin/bash
MYSQL=/usr/local/mysql/bin/mysql
MYSQL_HOST=localhost
MYSQL_USER=root
MYSQL_PASSWORD=1111
CHECK_TIME=3
#mysql is working MYSQL_OK is 1 , mysql down MYSQL_OK is 0
MYSQL_OK=1
check_mysql_helth (){
$MYSQL -h $MYSQL_HOST -u $MYSQL_USER -p${MYSQL_PASSWORD} -e "show status;" &>/dev/null
if [ $? -eq 0 ] ;then
MYSQL_OK=1
else
MYSQL_OK=0
fi
return $MYSQL_OK
}
while [ $CHECK_TIME -ne 0 ]
do
check_mysql_helth
if [ $MYSQL_OK -eq 1 ] ; then
exit 0
fi
if [ $MYSQL_OK -eq 0 ] && [ $CHECK_TIME -eq 1 ];then
/etc/init.d/keepalived stop
exit 1
fi
let CHECK_TIME--
sleep 1
done
版本三：检查多次
# vim /root/keepalived_check_mysql.sh
#!/bin/bash
MYSQL=/usr/local/mysql/bin/mysql
MYSQL_HOST=localhost
MYSQL_USER=root
MYSQL_PASSWORD=1111
CHECK_TIME=3
#mysql is working MYSQL_OK is 1 , mysql down MYSQL_OK is 0
MYSQL_OK=1
check_mysql_helth (){
$MYSQL -h $MYSQL_HOST -u $MYSQL_USER -p${MYSQL_PASSWORD} -e "show status;" &>/dev/null
if [ $? -eq 0 ] ;then
MYSQL_OK=1
else
MYSQL_OK=0
fi
return $MYSQL_OK
}
while [ $CHECK_TIME -ne 0 ]
do
check_mysql_helth
if [ $MYSQL_OK -eq 1 ] ; then
exit 0
fi
let CHECK_TIME--
sleep 1
done
/etc/init.d/keepalived stop
exit 1
# chmod 755 /root/keepalived_check_mysql.sh
两边均启动keepalived
日志查看脚本是否被执行
# tail -f /var/log/messages
Jun 19 15:20:19 xen1 Keepalived_vrrp[6341]: Using LinkWatch kernel netlink reflector...
Jun 19 15:20:19 xen1 Keepalived_vrrp[6341]: VRRP sockpool: [ifindex(2), proto(112), fd(11,12)]
Jun 19 15:20:19 xen1 Keepalived_vrrp[6341]: VRRP_Script(check_run) succeeded