前言: 一php朋友的公司没有运维，所以运维这一块很蛋痛，于是应他的请求，写上一些HA的东西在此，方便他查看
原理
master 192.168.1.21
backup 192.168.1.21
vip 192.168.1.80
软件安装
master and backup 都要
yum install libnl libnl-devel openssl-devel -y
tar xvf keepalived-1.2.12.tar.gz && cd keepalived-1.2.12
#centos 6.7
./configure --sysconf=/etc \
--with-kernel-dir=/usr/src/kernels/2.6.32-573.el6.x86_64
make -j2 && make install
ln -s /usr/local/sbin/keepalived /sbin/
chkconfig --add keepalived
chkconfig --level 35 keepalived on
master上的keepalived 相关配置
backup 上的keepalived 相关配置
backup 的脚本也是基本相同
只有
state MASTER -> state BACKUP
priority 100 -> 变小点 eg priority 80
nopreempt 设置在谁身上 他就是老大，就一直向外提供服务 所以建议写在backup上，也就是master出故障后，一直就先backup提供服务，
vim /etc/keepalived/keepalived.conf
!cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived master
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script check_httpd {
script "killall -0 httpd"
interval 2
}
vrrp_instance HA_1 {
state MASTER
interface eth0
virtual_router_id 80
priority 100
advert_int 2
authentication {
auth_type PASS
auth_pass 1111
}
notify_mster "/etc/keepalived/master.sh"
notify_backup "/etc/keepalived/backup.sh"
notify_fault "/etc/keepalived/fault.sh"
track_script {
check_httpd
}
virtual_ipaddress {
192.168.1.80/24 dev eth0
}
nopreempt #设置在谁身上 他就是老大，就一直向外提供服务 所以建议写在backup上，也就是master出故障后，一直就先backup提供服务，
}
这几个看你的情况分别写上
notify_mster “/etc/keepalived/master.sh”
notify_backup “/etc/keepalived/backup.sh”
notify_fault “/etc/keepalived/fault.sh”
##
结果
###keepalived 选项说明
! ConfigurationFile for keepalived
global_defs {
notification_email{
[email protected]
#指定keepalived在发生切换时需要发送email到的对象，一行一个
}
notification_email_from [email protected]#指定发件人
smtp_server 127.0.0.1 #指定smtp服务器地址
smtp_connect_timeout 30#指定smtp连接超时时间
router_id LVS_DEVEL #运行keepalived机器的一个标识
}
vrrp_scriptcheck_nginx {
script"/etc/keepalived/monitor_nginx.sh" #切换脚本
interval 2#间隔几秒
weight 2#权重
}
vrrp_instanceVI_1 {
state MASTER#指定那个为master，那个为backup
#nopreempt不抢占
interface eth0#设置实例绑定的网卡
virtual_router_id 51 #VPID标记
mcast_src_ip 172.16.2.195 #本机IP 与从不同
priority 100#优先级，另一台改为90 与从不同
advert_int 1#检查间隔，默认1s
#认证
authentication {
auth_type PASS
auth_pass chtopnet
}
track_script {
check_nginx#指定应用的脚本
}
virtual_ipaddress {
172.16.2.1#设置虚拟IP
}
}
监控脚本
vim/etc/keepalived/monitor_nginx.sh
#!/bin/bash
PROC=`/usr/sbin/lsof -i:80 | wc -l`
if [ $PROC -eq 0 ]; then
/usr/local/nginx/sbin/nginx
sleep 5
PROC=`/usr/sbin/lsof -i:80 | wc -l`
[ $PROC -eq 0 ] && /etc/init.d/keepalived stop
Fi