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Nginx Master: 192.168.128.134
Nginx Backup: 192.168.128.138
VIP:192.168.128.177
Nginx安装见nginx安装配置文档
Master与Backup的Nginx配置一致.
在MASTER跟BACKUP上安装Keepalived:
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#tar zxvf keepalived-1.1.15.tar.gz -C ../software
#cd ../software/keepalived-1.1.15
#./configure –prefix=/usr/local/keepalived && make && make install
#cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
#cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
#mkdir /etc/keepalived
#cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
#cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
#service keepalived start|stop #做成系统启动服务方便管理.
修改MASTER 的keepalived.conf
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#vim /etc/keepalived/keepalived.conf
vrrp_script chk_http_port {
script "/usr/local/scripts/nginx_pid.sh" ###监控脚本
interval 2 ###监控时间
weight 2
}
vrrp_instance VI_1 {
state MASTER ### 设置为主
interface eth0 ### 监控网卡
virtual_router_id 51 ### 这个两台服务器必须一样
priority 101 ### 权重值MASTRE一定要高于BAUCKUP
authentication {
auth_type PASS ### 加密
auth_pass test ### 加密的密码，两台服务器一定要一样，不然会出错
}
track_script {
chk_http_port ### 执行监控的服务
}
virtual_ipaddress {
192.168.128.177 ### VIP 地址
}
}
修改BACKUP keepalived.conf
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#vim /etc/keepalived/keepalived.conf
vrrp_script chk_http_port {
script "/opt/nginx_pid.sh"
interval 2
weight 2
}
vrrp_instance VI_1 {
state BACKUP ### 设置为备份机
interface eth0
virtual_router_id 51 ### 与 MASTRE 设置值一样
priority 80 ### 比 MASTRE权重值低
authentication {
auth_type PASS
auth_pass test ### 密码 与 MASTRE 一样
}
track_script {
chk_http_port
}
virtual_ipaddress {
192.168.128.177
}
}
编写监控nginx监控脚本
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#vim /usr/local/scripts/nginx_pid.sh
#!/bin/bash
A=`ps -C nginx --no-header |wc -l` ## 查看是否有 nginx进程 把值赋给变量A
if [ $A -eq 0 ];then ## 如果没有进程值得为 零
/usr/local/nginx/sbin/nginx
sleep 3
if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
killall keepalived ## 则结束 keepalived 进程
fi
fi
测试,分别在两个服务器 启动 nginx 和 keepalived
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#/usr/local/nginx/sbin/nginx
#/etc/init.d/keepalived start
监控 Nginx Mastaer 的日志
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May 12 17:33:44 localhost Keepalived_vrrp: Configuration is using : 35676 Bytes
May 12 17:33:44 localhost Keepalived: Starting VRRP child process, pid=1245
May 12 17:33:44 localhost Keepalived_vrrp: VRRP sockpool: [ifindex(2), proto(112), fd(8,9)]
May 12 17:33:45 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE
May 12 17:33:46 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE
May 12 17:33:46 localhost Keepalived_vrrp: VRRP_Instance(VI_1) setting protocol VIPs.
May 12 17:33:46 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.128.177
May 12 17:33:46 localhost avahi-daemon[2344]: Registering new address record for 192.168.128.177 on eth0.
May 12 17:33:46 localhost Keepalived_vrrp: Netlink reflector reports IP 192.168.128.177 added
监控 Nginx Backup 的日志
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May 11 22:28:21 localhost Keepalived: Starting Keepalived v1.1.15 (05/11,2010)
May 11 22:28:21 localhost Keepalived_vrrp: Using MII-BMSR NIC polling thread...
May 11 22:28:21 localhost Keepalived_vrrp: Registering Kernel netlink reflector
May 11 22:28:21 localhost Keepalived_vrrp: Registering Kernel netlink command channel
May 11 22:28:21 localhost Keepalived_vrrp: Registering gratutious ARP shared channel
May 11 22:28:21 localhost Keepalived: Starting VRRP child process, pid=27040
May 11 22:28:21 localhost Keepalived_vrrp: Opening file '/etc/keepalived/keepalived.conf'.
May 11 22:28:21 localhost Keepalived_vrrp: Configuration is using : 35538 Bytes
May 11 22:28:21 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Entering BACKUP STATE
May 11 22:28:21 localhost Keepalived_vrrp: VRRP sockpool: [ifindex(2), proto(112), fd(7,8)]
May 11 22:28:23 localhost Keepalived_vrrp: VRRP_Script(chk_http_port) succeeded
看日志可以看出，两台服务器的 MASTRE 和 BACUKUP 已经都正常了
现在我们把Master的Nginx停掉.查看Backup的日志
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May 11 22:28:21 localhost Keepalived: Starting VRRP child process, pid=27040
May 11 22:28:21 localhost Keepalived_vrrp: Opening file '/etc/keepalived/keepalived.conf'.
May 11 22:28:21 localhost Keepalived_vrrp: Configuration is using : 35538 Bytes
May 11 22:28:21 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Entering BACKUP STATE
May 11 22:28:21 localhost Keepalived_vrrp: VRRP sockpool: [ifindex(2), proto(112), fd(7,8)]
May 11 22:28:23 localhost Keepalived_vrrp: VRRP_Script(chk_http_port) succeeded
May 11 22:29:25 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE
May 11 22:29:26 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE
May 11 22:29:26 localhost Keepalived_vrrp: VRRP_Instance(VI_1) setting protocol VIPs.
May 11 22:29:26 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.128.177
可以看出backup已经变成master
现在再启动原来master的nginx,再查看backup的日志
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May 11 22:30:32 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Received higher prio advert
May 11 22:30:32 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Entering BACKUP STATE
May 11 22:30:32 localhost Keepalived_vrrp: VRRP_Instance(VI_1) removing protocol VIPs.
May 11 22:30:32 localhost avahi-daemon[2409]: Withdrawing address record for 192.168.128.177 on eth0.
可以看出又变回了backup.