首先，我们了解下nginx作为负载均衡器的优点:
1.实现了可弹性化的架构,在压力增大的时候可以临时添加tomcat服务器添加到这个架构里面去;
2.upstream具有负载均衡能力,可以自动判断下面的机器,并且自动踢出不能正常提供服务的机器;而Keepalvied可保证单个nginx负载均衡器的有效性,避免单点故障。
IP地址：
nginx(主负载均衡器):192.168.18.118
nginx(从负载均衡器):192.168.1.120
VIP地址:192.168.1.108
web1的IP:192.168.18.105
web2的IP:192.168.18.117
web3的IP:192.168.1.121
软件:
nginx-0.7.17.tar.gz
prce-7.7.tar.gz
mysql
php
一、首先分别在3台tomcat主机上布置环境,安装nginx+php+mysql,具体步骤为:
略
二、分别在二台nginx负载均衡器上安装nginx及配置
下载及安装nginx:
这里贴上nginx.conf配置文件,不加任何说明。
二个nginx负载均衡器的文件一样,配置完成后分别用/usr/local/nginx/sbin/nginx启动｡
user www www;
worker_processes 1;
pid /usr/local/nginx/logs/nginx.pid;
worker_rlimit_nofile 51200;
events
{
use epoll;
worker_connections 51200;
}
http{
include mime.types;
default_type application/octet-stream;
server_names_hash_bucket_size 128;
client_header_buffer_size 32k;
large_client_header_buffers 4 32k;
client_max_body_size 8m;
sendfile on;
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;
upstream backend
{
server 192.168.18.117;
server 192.168.18.105;
server 192.168.1.121;
}
server {
listen 80;
server_name test.com www.test.com;
location / {
root /usr/local/nginx/www ;
index index.jsp index.htm index.html;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_pass http://backend;
}
#location /nginx {
#access_log on;
#auth_basic "NginxStatus";
#auth_basic_user_file /usr/local/nginx/htpasswd;
#}
log_format access '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent"
$http_x_forwarded_for';
access_log /usr/local/nginx/logs/access.log access;
}
}
三、在二台Nginx机上安装及配置keepalived,做双机互备｡
将keepalived做成启动脚务,方便管理:
在二台Nginx上,我分别贴出keepalived.conf配置文件,配置完成后分别用service keepalived start启动｡检验keepalived是否成功可用命令
以上三步完成nginx负载均衡设置后,就是检测了,大家可任意停掉其中一台的任何服务;在正常结果中大家应该发现,其中任意一台服务器宕机后,不影响整个系统的运作｡