通过lvs+keepalived实现对mysql的负载均衡高可用
1、摘要
本文主要通过lvs+keepalived实现对mysql的负载均衡高可用。
keepalived是基于VRRP协议（虚拟路由冗余协议），目的是模拟路由器双机。
2、安装
1）、软件包准备
ipvsadm-1.26.tar.gz
mysql-5.5.28.tar.gz
cmake-2.8.11.2.tar.gz
keepalived-1.2.13.tar.gz
2)、配置Director Server
a、检查kernel是否已经支持LVS的ipvs模块
# modprobe -l |grep ipvs
kernel/net/netfilter/ipvs/ip_vs.ko
kernel/net/netfilter/ipvs/ip_vs_rr.ko
kernel/net/netfilter/ipvs/ip_vs_wrr.ko
kernel/net/netfilter/ipvs/ip_vs_lc.ko
kernel/net/netfilter/ipvs/ip_vs_wlc.ko
kernel/net/netfilter/ipvs/ip_vs_lblc.ko
kernel/net/netfilter/ipvs/ip_vs_lblcr.ko
kernel/net/netfilter/ipvs/ip_vs_dh.ko
kernel/net/netfilter/ipvs/ip_vs_sh.ko
kernel/net/netfilter/ipvs/ip_vs_sed.ko
kernel/net/netfilter/ipvs/ip_vs_nq.ko
kernel/net/netfilter/ipvs/ip_vs_ftp.ko
kernel/net/netfilter/ipvs/ip_vs_pe_sip.ko
b、在Director Server中安装LVS
# ln -s /usr/src/kernels/2.6.32-431.el6.x86_64/ /usr/src/linux #解决ipvsadm找不到内核
# yum install -y libnl*
# yum install -y popt*
# rpm -ivh popt-static-1.13-7.el6.x86_64.rpm #前三步是解决安装ipvsadm-1.26报错的软件包
# tar zxvf ipvsadm-1.26.tar.gz
# cd ipvsadm-1.26
# make
# make install
# ipvsadm --help #出现ipvsadm帮助提示表示ipvsadm已经安装成功
c、在Director Server中配置VIP，route、路由转发等
vim /etc/init.d/lvsDR
#!/bin/sh
# description: Start LVS of Director server
VIP=10.0.2.200
chmod 755 /etc/rc.d/init.d/functions
/etc/rc.d/init.d/functions
case "$1" in
start)
# set the Virtual IP Address and sysctl parameter
/sbin/ifconfig eth0:0 $VIP broadcast $VIP netmask 255.255.255.255 up
/sbin/route add -host $VIP dev eth0:0
echo "1" >/proc/sys/net/ipv4/ip_forward
;;
stop)
echo "0" >/proc/sys/net/ipv4/ip_forward
/sbin/route del -host $VIP dev eth0:0
/sbin/ifconfig eth0:0 down
;;
*)
echo "Usage: $0 {start|stop}"
exit 1
esac
# chmod 755 /etc/init.d/lvsDR
# /etc/init.d/lvsDR start
d、在Director Server中安装配置keepalived
# yum install openssl* -y
# tar zxvf keepalived-1.2.13.tar.gz
# cd keepalived-1.2.13
# ./configure --prefix=/usr/local/keepalived
# make && make install
# mv /usr/local/keepalived/etc/keepalived/keepalived.conf /usr/local/keepalived/etc/keepalived/keepalived.conf.bak
# vim /usr/local/keepalived/etc/keepalived/keepalived.conf
global_defs {
router_id LVS_MySQL
}
vrrp_instance VI_MYSQL {
state MASTER
interface eth0
virtual_router_id 100
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.2.200
}
}
virtual_server 10.0.2.200 3306 {
delay_loop 6
lb_algo rr
lb_kind DR
# nat_mask 255.255.0.0
# persistence_timeout 50
protocol TCP
real_server 10.0.2.203 3306 {
weight 3
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 3306
}
}
real_server 10.0.2.204 3306 {
weight 3
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 3306
}
}
}
# 启动keepalived
/usr/local/keepalived/sbin/keepalived -f /usr/local/keepalived/etc/keepalived/keepalived.conf
# 备注：在BACKUP Director Server上安装配置keepalived同MASTER Director Server配置基本一样，需要修改的地方在keepalived配置文件中，将state MASTER => state BACKUP,priority 100 => priority 99
3)、配置Real Server
a、mysql的安装以及主从配置参考“MySQL同步复制”一文
b、配置vip和arp
# vim /etc/init.d/lvsrs
#!/bin/bash
#description : Start Real Server
VIP=10.0.2.200
/etc/rc.d/init.d/functions
case "$1" in
start)
echo " Start LVS of Real Server"
/sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up
/sbin/route add -host $VIP dev lo:0
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
sysctl -p
;;
stop)
/sbin/ifconfig lo:0 down
/sbin/route del -host $VIP dev lo:0
echo "close LVS Director server"
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 "Usage: $0 {start|stop}"
exit 1
esac
# chmod 755 /etc/init.d/lvsrs
# /etc/init.d/lvsrs start
4）、测试
略