keepalived介绍：Keepalived的作用是检测web服务器 的状态，如果有一台web服务器死机，或工作出现故障，Keepalived将检测到，并将有故障的web 服务器从系统中剔除，当web服务器工作正常后Keepalived自动将web服务器加入到服务器群中，这些工作全部自动完成，不需要人工干涉，需要人 工做的只是修复故障的web服务器。
下载 安装包
1、
安装环境
yum -y install openssl-devel
2、
安装
# tar -zxvf keepalived-1.2.24.tar.gz
# cd keepalived-1.2.24
# ./configure --prefix=/opt/mysql/keepalived --with-kernel-dir=/usr/src/kernels/2.6.32-573.26.1.el6.x86_64/
--prefix：安装路径
--with-kernel-dir：这个是重要的参数，这个参数并不表示我们要把Keepalived统进内核，而是指使用内核源码里面的头文件，也就是include目录。
2.6.32-573.26.1.el6.x86_64 可以通过 uname -r 命令查询到
# make && make install
3、
配置
默认情况下keepalived启动时会去/etc/keepalived目录下找配置文件，将需要的配置文件拷贝到指定位置
# cp /opt/mysql/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
# cp /opt/mysql/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
# chmod +x /etc/rc.d/init.d/keepalived
# chmod +x /etc/sysconfig/keepalived
# mkdir /etc/keepalived
# cp /opt/mysql/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
# cp /opt/mysql/keepalived/sbin/keepalived /usr/sbin/
# chmod +x /usr/sbin/keepalived
4、
启动/停止
# service keepalived start
# service keepalived stop
# service keepalived restart
###以下搭建mysql的 lvs+keepalived+mysql 用到 #########
5、
安装配置lvs 见 lvs安装
6
、
配置
172.31.107.59/60/61 master/slave
7、
LVS配置
vim /etc/init.d/realserver
SNS_VIP=172.31.107.240
/etc/rc.d/init.d/functions
case "$1" in
start)
ifconfig eth0:0 $SNS_VIP netmask 255.255.0.0 broadcast $SNS_VIP
/sbin/route add -host $SNS_VIP dev eth0:0
echo "1" >/proc/sys/net/ipv4/conf/eth0/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/eth0/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
sysctl -p >/dev/null 2>&1
echo "RealServer Start OK"
;;
stop)
ifconfig eth0:0 down
route del $SNS_VIP >/dev/null 2>&1
echo "0" >/proc/sys/net/ipv4/conf/eth0/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/eth0/arp_announce
echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
echo "RealServer Stoped"
;;
*)
echo "Usage: $0 {start|stop}"
exit 1
esac
exit 0
chmod 755 realserver
chmod 755 functions
service realserver start
检查LVS的状态
ipvsadm -Ln