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准备工作
1、设备分配
192.168.137.100 master
192.168.137.150 backup
192.168.137.254 vip
2、两台设备均安装keepalived
| 1 | yum install -y keepalived |
3、两台设备均安装nginx
| 1 | yum install -y nginx |
主设备配置
1、编辑keepalived配置文件
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | [root@juispan ~] # > /etc/keepalived/keepalived.conf [root@juispan ~] # vi /etc/keepalived/keepalived.conf global_defs { notification_email { ##出现问题后接收提示的邮箱 test @ test .com } notification_email_from root@test2.com ##发件人 smtp_server 127.0.0.1 ##邮件服务器 smtp_connect_timeout 30 ##延时 router_id LVS_DEVEL } vrrp_script chk_nginx { ##检查服务状态 script "/usr/local/sbin/check_ng.sh" interval 3 } vrrp_instance VI_1 { ##定义master相关配置 state MASTER ##设定角色 interface ens33 ##指定发送vrrp包的网卡 virtual_router_id 51 ##定义VRRP RID，要和从设备一致 priority 100 ##优先级，越大越优 advert_int 1 authentication { auth_type PASS ##定义认证类型 auth_pass 123456 ##认证口令 } virtual_ipaddress { ##VIP 192.168.137.254 } track_script { chk_nginx ##加载定义的chk_nginx脚本 } } |
2、编辑监控脚本
如果进程里面没发现nginx那就代表着服务宕机了，然后脚本自动的再次启动nginx服务。 如果服务还是不可以启动，就把启动报错日志输入到指定的位置，然后为防止“脑裂”就把keepalived也关闭。
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | [root@juispan ~] # vi /usr/local/sbin/check_ng.sh #!/bin/bash #时间变量，用于记录日志 d=` date -- date today +%Y%m%d_%H:%M:%S` #计算nginx进程数量 n=` ps -C nginx --no-heading| wc -l` #如果进程为0，则启动nginx，并且再次检测nginx进程数量， #如果还为0，说明nginx无法启动，此时需要关闭keepalived if [ $n - eq "0" ]; then /etc/init .d /nginx start n2=` ps -C nginx --no-heading| wc -l` if [ $n2 - eq "0" ]; then echo "$d nginx down,keepalived will stop" >> /var/log/check_ng .log systemctl stop keepalived fi fi [root@juispan ~] # chmod 755 /usr/local/sbin/check_ng.sh |
3、启动服务
| 1 2 3 4 5 6 | [root@juispan ~] # systemctl start keepalived [root@juispan ~] # ps aux | grep keep root 2416 0.0 0.1 111708 1316 ? Ss 19:29 0:00 /usr/sbin/keepalived -D root 2417 0.0 0.2 111708 2560 ? S 19:29 0:00 /usr/sbin/keepalived -D root 2418 0.0 0.1 111708 1616 ? S 19:29 0:00 /usr/sbin/keepalived -D root 2479 0.0 0.0 112664 976 pts /0 S+ 19:29 0:00 grep --color=auto keep |
4、清空策略并验证
| 1 2 3 4 5 6 7 8 9 10 11 12 13 | [root@juispan ~] # systemctl stop firewalld [root@juispan ~] # systemctl disable firewalld Removed symlink /etc/systemd/system/basic .target.wants /firewalld .service. Removed symlink /etc/systemd/system/dbus-org .fedoraproject.FirewallD1.service. [root@juispan ~] # setenforce 0 [root@juispan ~] # less /var/log/messages ##查看日志 [root@juispan ~] # ip addr 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link /ether 00:0c:29:0c:4d:a8 brd ff:ff:ff:ff:ff:ff inet 192.168.137.100 /24 brd 192.168.137.255 scope global ens33 valid_lft forever preferred_lft forever inet 192.168.137.254 /32 scope global ens33 ##已加载VIP valid_lft forever preferred_lft forever |
从设备配置
1、关闭防火墙
| 1 2 3 4 5 | [root@localhost ~] # systemctl stop firewalld [root@localhost ~] # systemctl disable firewalld Removed symlink /etc/systemd/system/dbus-org .fedoraproject.FirewallD1.service. Removed symlink /etc/systemd/system/basic .target.wants /firewalld .service. [root@localhost ~] # setenforce 0 |
2、配置keepalived文件
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | [root@localhost ~] # > /etc/keepalived/keepalived.conf [root@localhost ~] # vi /etc/keepalived/keepalived.conf global_defs { notification_email { test @ test .com } notification_email_from root@ test .com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_script chk_nginx { script "/usr/local/sbin/check_ng.sh" interval 3 } vrrp_instance VI_1 { state BACKUP interface ens33 virtual_router_id 51 priority 90 advert_int 1 authentication { auth_type PASS auth_pass 123456 } virtual_ipaddress { 192.168.137.254 } track_script { chk_nginx } } |
3、编写启动脚本
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | [root@localhost ~] # vi /usr/local/sbin/check_ng.sh #时间变量，用于记录日志 d=` date -- date today +%Y%m%d_%H:%M:%S` #计算nginx进程数量 n=` ps -C nginx --no-heading| wc -l` #如果进程为0，则启动nginx，并且再次检测nginx进程数量， #如果还为0，说明nginx无法启动，此时需要关闭keepalived if [ $n - eq "0" ]; then systemctl start nginx n2=` ps -C nginx --no-heading| wc -l` if [ $n2 - eq "0" ]; then echo "$d nginx down,keepalived will stop" >> /var/log/check_ng .log systemctl stop keepalived fi fi [root@localhost ~] # chmod 755 /usr/local/sbin/check_ng.sh |
4、启动服务
| 1 2 3 4 5 6 | [root@localhost ~] # systemctl start keepalived [root@localhost ~] # ps aux | grep keepalived root 3266 0.0 0.1 111708 1308 ? Ss 21:30 0:00 /usr/sbin/keepalived -D root 3267 0.0 0.2 111708 2548 ? S 21:30 0:00 /usr/sbin/keepalived -D root 3268 0.1 0.1 111708 1620 ? S 21:30 0:00 /usr/sbin/keepalived -D root 3321 0.0 0.0 112664 976 pts /1 S+ 21:30 0:00 grep --color=auto keepalived |
测试高可用
1、编辑nginx主页
| 1 | [root@juispan ~] # echo "this is master" > /usr/share/nginx/html/index.html |
| 1 | [root@localhost ~] # echo "this is backup" > /usr/share/nginx/html/index.html |
2、客户端测试
3、主设备模拟宕机，关闭keepalived服务
除了配置nginx的高可用，也可以配置其他服务的高可用，比如mysql的高可用，但前提是一定要保证双方的数据是一致的。如果主mysql宕机，从mysql的数据一定会和主设备不一致。
本文转自Grodd51CTO博客，原文链接：http://blog.51cto.com/juispan/1964009，如需转载请自行联系原作者