参考：
搭建环境:
192.168.127.141 （master nginx+keepalived+tomcat）
192.168.127.130 （backup nginx+keepalived+tomcat ）
vip 192.168.127.100 (实际环境中这个ip需要是个公网地址供客户端访问)
实现的功能有：
1）、Master服务器没挂，则Master占有vip且nginx运行在Master上
2）、Master服务器挂了，则backup抢占vip且在backup上运行nginx服务
3）、如果master服务器上的nginx服务挂了，则vip资源转移到backup服务器上
4）、检测后端服务器的健康状态
master:
一 安装nginx和keepalived:
1 安装keepalived和编译安装nginx
yum -y install keepalivedwget http://nginx.org/download/nginx-1.6.2.tar.gz[root@ ~]#tar xf nginx-1.6.2.tar.gz[root@ ~]#yum -y groupinstall "Development tools" "Server Platform Development"[root@ ~]#yum -y install pcre-devel[root@ ~]# cd nginx-1.6.2[root@ nginx]# groupadd nginx[root@ nginx]# useradd -r -g nginx nginx[root@ nginx]#./configure \--prefix=/usr\--sbin-path=/usr/sbin/nginx\--conf-path=/etc/nginx/nginx.conf \--error-log-path=/var/log/nginx/error.log \--http-log-path=/var/log/nginx/access.log \--pid-path=/var/run/nginx/nginx.pid \--lock-path=/var/lock/nginx.lock \--user=nginx \--group=nginx \--with-http_ssl_module \--with-http_flv_module \--with-http_stub_status_module \--with-http_gzip_static_module \--http-client-body-temp-path=/var/tmp/nginx/client/\--http-proxy-temp-path=/var/tmp/nginx/proxy/\--http-fastcgi-temp-path=/var/tmp/nginx/fcgi/\--http-uwsgi-temp-path=/var/tmp/nginx/uwsgi\--http-scgi-temp-path=/var/tmp/nginx/scgi\--with-pcremake && make install
2 编辑nginx的启动脚本
vi /etc/init.d/nginx#!/bin/bash# chkconfig: - 30 21# description: http service.# Source Function Library. /etc/init.d/functions# Nginx SettingsNGINX_SBIN="/usr/local/nginx/sbin/nginx"NGINX_CONF="/usr/local/nginx/conf/nginx.conf"NGINX_PID="/usr/local/nginx/logs/nginx.pid"RETVAL=0prog="Nginx"start() { echo -n $"Starting $prog: " mkdir -p /dev/shm/nginx_temp daemon $NGINX_SBIN -c $NGINX_CONF RETVAL=$? echo return $RETVAL}stop() { echo -n $"Stopping $prog: " killproc -p $NGINX_PID $NGINX_SBIN -TERM rm -rf /dev/shm/nginx_temp RETVAL=$? echo return $RETVAL}reload(){ echo -n $"Reloading $prog: " killproc -p $NGINX_PID $NGINX_SBIN -HUP RETVAL=$? echo return $RETVAL}restart(){ stop start}configtest(){ $NGINX_SBIN -c $NGINX_CONF -t return 0} 3 修改keepalived.conf配置文件
global_defs { notification_email { root@localhost } notification_email_from admin@localhost smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LTT}vrrp_script chk_nginx { #检测nginx服务是否在运行有很多方式，比如进程，用脚本检测等等 script "killall -0 nginx" #用shell命令检查nginx服务是否存在 interval 1 #时间间隔为1秒检测一次 weight -2 #当nginx的服务不存在了，就把当前的权重-2 fall 2 #测试失败的次数 rise 1 #测试成功的次数}vrrp_instance IN_1 { state MASTER interface eth0 virtual_router_id 22 priority 100 advert_int 1 authentication { auth_type PASS auth_pass aaaa } virtual_ipaddress { 192.168.127.100 } track_script { chk_nginx #引用上面的vrrp_script定义的脚本名称}}
4 启动keepalive和nginx服务
/etc/init.d/nginx start
/etc/init.d/keepalived start
Backup：
1、安装keepalived和编译安装nginx
同master一样（第一步和第二步）
3 修改keepalived配置文件
先从master上面拷贝这个配置文件然后更改
vim keepalived.conf #此配置文件是从Master服务器上copy过来，只需小小改动
state BACKUP #把这里原先的MASTER改成BACKUP
priority 99 #把这里原先的100改成99
4 开启服务
/etc/init.d/nginx start
/etc/init.d/keepalived start
#######################################################################################
两台服务器安装tomcat:
详细过程见：
二 在master 和backup 两个服务器上面配置nginx 负载均衡
BACKUP: tcp_nopush on; keepalive_timeout 60; tcp_nodelay on; fastcgi_connect_timeout 300; fastcgi_send_timeout 300; fastcgi_read_timeout 300; fastcgi_buffer_size 64k; fastcgi_buffers 4 64k; fastcgi_busy_buffers_size 128k; fastcgi_temp_file_write_size 128k; gzip on; gzip_min_length 1k; gzip_buffers 4 16k; gzip_http_version 1.0; gzip_comp_level 2; gzip_types text/plain application/x-javascript text/css application/xml; gzip_vary on; # include vhosts/*.conf; upstream web_server { server 192.168.127.130:8080 weight=1; server 192.168.127.141:8080 weight=1;} server { listen 80; server_name 192.168.127.130; index index.html index.htm; root /usr/local/nginx/html/ROOT; location / { proxy_pass http://web_server; proxy_set_header Host $host; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Real-IP $remote_addr; }}} MASTER: tcp_nopush on; keepalive_timeout 60; tcp_nodelay on; fastcgi_connect_timeout 300; fastcgi_send_timeout 300; fastcgi_read_timeout 300; fastcgi_buffer_size 64k; fastcgi_buffers 4 64k; fastcgi_busy_buffers_size 128k; fastcgi_temp_file_write_size 128k; gzip on; gzip_min_length 1k; gzip_buffers 4 16k; gzip_http_version 1.0; gzip_comp_level 2; gzip_types text/plain application/x-javascript text/css application/xml; gzip_vary on; # include vhosts/*.conf; upstream web_server { server 192.168.127.130:8080 weight=1; server 192.168.127.141:8080 weight=1;} server { listen 80; server_name 192.168.127.141; index index.html index.htm; root /usr/local/nginx/html/ROOT; location / { proxy_pass http://web_server; proxy_set_header Host $host; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Real-IP $remote_addr; }}} 然后两边分别重启nginx服务
三 测试
1 把master上面的nginx服务停掉，看客户端能否正常访问网站并且查看vip是否会移动到backup上面
2 把master 上面的keepalived 服务停掉 看客户端能否正常访问网站并且查看vip是否会移动到backup上面
3 把其中一个web服务停掉，看是否还能正常访问web
用浏览器访问http://192.168.127.100验证即可