Nginx+keepalived双机热备

花蜻宽

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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 <span style="white-space:pre"> </span>## 如果没有进程值得为 零  
  
• <span style="white-space:pre">  </span>/usr/local/nginx/sbin/nginx  
  
• <span style="white-space:pre">  </span>sleep 3  
  
• <span style="white-space:pre">  </span>if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then  
  
• <span style="white-space:pre">  </span>killall keepalived ## 则结束 keepalived 进程  
  
• <span style="white-space:pre">  </span>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.