1.nginx是一款轻量级兼备高性能的Http和反向代理服务器。所谓反向代理就是指用户发起访问请求，由代理服务器接受，然后将请求转发给正式服务器，并且将正式服务器处理完的数据返回给客户单，此时代理服务器就表现为一个服务器。
进入nginx的安装目录后，输入相关命令，一个窗口一闪而过，在任务管理器中可以找到它的进程。
浏览器输入localhost，可以看到nginx的欢迎页面！
修改nginx的配置文件，
worker_processes:工作进程个数，
worker_connections:单个进程最大连接数，
server:每一个server相当于一个代理服务器，
listern:监听端口，默认80，
server_name:当前服务的域名，可以有多个，用空格分割，
location:表示匹配的路径，配置/ 表示所有请求都被匹配到这里，
index:当没有指定主页时，默认会选择这个指定的文件，可多个，空格分割 ，
proxy_pass:请求转向自定义的服务器列表，
upstream name{} :服务器集群名称
- 然后再cmd中输入命令nginx -s reload重启nginx;
- 部署三个Tomcat，分别修改server.xml 和context.xml
server.xml依次修改 Server的port为8005,8006,8007 ，Connector的port为8081 8082 8083，8009 8010 8011
context.xml增加
并在webappsROOT下增加session.jsp ,加上标记tomcat 1 tomcat 2 tomcat 3
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>shared session</title> </head> <body> <br>session id=<%=session.getId()%> <br>tomcat 1 </body> </html>
将如下几个jar包复制到${TOMCAT_HOME}/lib下
tomcat-redis-session-manager-VERSION.jar jedis-2.5.2.jar commons-pool2-2.2.jar
3.修改Ngnix的配置文件增加负载均衡配置
#user nobody;
#nginx进程数,建议设置为等于CPU总核心数
worker_processes 4;
error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#进程pid文件
pid logs/nginx.pid;
events {
worker_connections 65535;
}
http {
include mime.types;
default_type application/octet-stream;
#log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
upstream mt.com {
#upstream的负载均衡,weight是权重,可根据机器配置定义权重.weight参数表示权值,权值越高被分配的几率越大.
server 127.0.0.1:8081 weight=1;
server 127.0.0.1:8082 weight=2;
server 127.0.0.1:8083 weight=3;
}
server {
listen 80;
server_name localhost;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
#root html;
index index.html index.htm;
proxy_pass http://mt.com;
proxy_set_header X-Real-IP $remote_addr;
#允许客户端请求的最大单文件字节数
client_max_body_size 100m;
}
#error_page 404 /404.html;
# redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
# proxy the PHP scripts to Apache listening on 127.0.0.1:80
#
#location ~ .php$ {
# proxy_pass http://127.0.0.1;
#}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
#location ~ .php$ {
# root html;
# fastcgi_pass 127.0.0.1:9000;
# fastcgi_index index.php;
# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;
# include fastcgi_params;
#}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /.ht {
# deny all;
#}
}
# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
# listen 8000;
# listen somename:8080;
# server_name somename alias another.alias;
# location / {
# root html;
# index index.html index.htm;
# }
#}
# HTTPS server
#
#server {
# listen 443 ssl;
# server_name localhost;
# ssl_certificate cert.pem;
# ssl_certificate_key cert.key;
# ssl_session_cache shared:SSL:1m;
# ssl_session_timeout 5m;
# ssl_ciphers HIGH:!aNULL:!MD5;
# ssl_prefer_server_ciphers on;
# location / {
# root html;
# index index.html index.htm;
# }
#}
}
4.启动redis,tomcat1,tomcat2,tomcat3 访问localhost/session.jsp且不断刷新
可以看到每次刷新都可能访问不同的tomcat，实现了负载均衡，而且session都是一致的，保证了session的一致性
原文参照： https://www.cnblogs.com/zhrxidian/p/5432886.html
https://www.cnblogs.com/linjiqin/p/5761281.html
http://blog.csdn.net/lipc_/article/details/52766884
https://www.cnblogs.com/machanghai/p/5956195.html