介绍：

keepalived是一个类似于layer3, 4 & 5交换机制的软件，也就是我们平时说的第3层、第4层和第5层交换。Keepalived是自动完成，不需人工干涉。主要提供loadbalancing(负载均衡)和 high-availability(高可用)功能，负载均衡实现需要依赖Linux的虚拟服务内核模块(ipvs)，而高可用是通过VRRP协议实现多台机器之间的故障转移服务。

IP分配：

Master:172.16.1.11Salve:172.16.1.21VIP:172.16.1.250

安装

1.Nginx安装

参考：本人前面发的Nginx安装文档

2.keepalived安装

2.1安装包下载

keepalived-1.2.19(http://image.wohenniucha.com/upload/2018/05/keepalived-1.2.19.tar.gz)

2.2开始安装

cd /main/softtar zxvf keepalived-1.2.19.tar.gzcd keepalived-1.2.19./configure --prefix=/main/server/keepalivedmake && make install

2.3配置为服务和开机启动

#复制keepalived启动文件到默认路径cp /main/server/keepalived/sbin/keepalived /usr/sbin/cp /main/server/keepalived/etc/sysconfig/keepalived /etc/sysconfig/cp /main/server/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/chmod 755 /etc/init.d/keepalivedchkconfig --add keepalivedchkconfig --level 345 keepalived on

2.4创建Nginx监控脚本

vi /main/server/nginx/conf/check_nginx.sh##复制以下脚本#!/bin/bash A=`ps -C nginx --no-header|wc -l` if [ $A -eq 0 ];then /main/server/nginx/sbin/nginxsleep 3if [ `ps -C nginx --no-header|wc -l` -eq 0 ];then killall keepalived fi fi#赋予执行权限chmod 755 /main/server/nginx/conf/check_nginx.sh

2.5配置keepalived

2.5.1主节点配置

vi /etc/keepalived/keepalived.conf##复制以下配置文件!Configuration File for keepalivedglobal_defs { notification_email { admin@wohenniucha.com} notification_email_from admin@wohenniucha.com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id NGINX1_DEVEL}vrrp_script chk_nginx { script "/main/server/nginx/conf/check_nginx.sh" interval 2 weight 2}vrrp_instance VI_1 { state MASTER nopreempt interface eth0 virtual_router_id 31 mcast_src_ip 172.18.1.11 priority 150 advert_int 1 authentication { auth_type PASS auth_pass 002233 } virtual_ipaddress { 172.18.1.250 }track_script { chk_nginx }}

2.5.2备节点配置

vi /etc/keepalived/keepalived.conf##复制以下配置文件! Configuration File for keepalivedglobal_defs { notification_email { admin@wohenniucha.com} notification_email_from admin@wohenniucha.com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id NGINX2_DEVEL}vrrp_script chk_nginx { script "/main/server/nginx/conf/check_nginx.sh"  interval 2 weight 2}vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 31 mcast_src_ip 172.18.1.21 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 002233 } virtual_ipaddress { 172.18.1.250 }track_script { chk_nginx }}

2.5.3重启服务

service keepalived start

2.6开放防火墙端口

iptables -I INPUT -p tcp --dport 80 -j ACCEPT iptables -I INPUT 3 -p vrrp -j ACCEPT/etc/rc.d/init.d/iptables save

2.7查看日志

日志文件在/var/log/messages