分别下载
tomcat
nginx
准备两个虚拟机：
server1 192.168.1.112
server2 192.168.1.64
Tomcat直接解压,运行,使用默认的8080端口
tar zxvf apache-tomcat-7.0.22.tar.gz
cd apache-tomcat-7.0.22/bin
./startup.sh访问http://192.168.1.112:8080和http://192.168.1.64:8080出现Tomcat首页即可
接下来安装nginx, nginx我就直接安装在server1上
nginx_upstream_jvm_route是一个Nginx的扩展模块，用来实现基于Cookie的SessionSticky的功能， 去SVN下载最新版
svn checkout http://nginx-upstream-jvm-route.googlecode.com/svn/trunk/ /root/dev/nginx-upstream-jvm-route-read-only解压nginx
tar zxvf nginx-1.1.14.tar.gzcd nginx-1.1.14运行
patch -p0 < /root/dev/nginx-upstream-jvm-route-read-only/jvm_route.patch./configure --prefix=/etc/nginx --with-http_stub_status_module --add-module=/root/dev/nginx-upstream-jvm-route-read-only/makemake install在nginx安装目录下的conf/目录新建一个文件proxy.conf(/etc/nginx/conf/proxy.conf), 内容如下:
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; client_max_body_size 10m; client_body_buffer_size 128k; proxy_connect_timeout 90; proxy_send_timeout 90; proxy_read_timeout 90; proxy_buffer_size 4k; proxy_buffers 4 32k; proxy_busy_buffers_size 64k; proxy_temp_file_write_size 64k;修改nginx配置文件/etc/nginx/conf/nginx.conf
完整配置如下
http { include mime.types; #反向代理配置 include proxy.conf; default_type application/octet-stream; sendfile on;keepalive_timeout 65; upstream server1{ server 192.168.1.112:8080 srun_id=tomcat1; server 192.168.1.64:8080 srun_id=tomcat2; jvm_route $cookie_JSESSIONID|sessionid reverse; } server { listen 80; server_name localhost; access_log /var/log/nginx/access.log; location ~ ^/NginxStatus/ { stub_status on; #Nginx 状态监控配置 access_log off; } location ~ ^/(WEB-INF)/ { deny all; } location / { root html; index index.html index.htm; proxy_pass http://server1; } location /doc { root /usr/share; autoindex on; allow 127.0.0.1; deny all; } location /images { root /usr/share; autoindex on; }具体配置说明请参考《轻量级WEB服务器Nginx》
然后运行nginx
/etc/nginx/sbin/nginx访问http://192.168.1.112/NginxStatus,可以看到nginx状态
然后修改tomcat配置文件, 打开apache-tomcat-7.0.22/conf/server.xml, 找到最下面的<Engine name="Catalina" defaultHost="localhost">节点, 修改为
server1
并插入如下配置
server2
...
jvmRoute="tomcat1"和nginx配置upstream中的srun_id对应membership中的address＝224.0.0.4为组播IP，集群中的tomcat通信之用receiver中的address设为本机IP，或auto，如果多个Tomcat在同一台电脑上，则要保证port端口不重复在两个tomcat的webapps目录下分别新建一个项目test,
/test
/test/index.jsp
/test/WEB-INF/
/test/WEB-INF/web.xml
index.jsp内容
web.xml<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>Insert title here <%=session.getId() %><%String msg = (String)session.getAttribute("msg");if(null == msg){ session.setAttribute("msg", "Hello!");}else{ session.setAttribute("msg", msg + 0);}%><%=session.getAttribute("msg") %>index.jsp 注意上面的distributable节点，表示该应用是在集群环境下的。
重启tomcat后在两台机子上访问http://192.168.1.112/test
从SessionId后面带的服务器名可以看到负载均衡的效果。
然后将server1上的tomcat停掉，再刷新页面，可以看到原来访问server1的页面成功地切换到了server2，而sessionId没有变，session中的msg也和原来一样。