Nginx + Tomcat + Session

分别下载

tomcat http://archive.apache.org/dist/tomcat/tomcat-7/v7.0.22/bin/apache-tomcat-7.0.22.tar.gz

nginx http://nginx.org/download/nginx-1.1.14.tar.gz

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.gz

cd 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/

make

make 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

<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat1">

并插入如下配置

<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster" 
                 channelSendOptions="8"> 
          <Manager className="org.apache.catalina.ha.session.DeltaManager" 
                   expireSessionsOnShutdown="false" 
                   notifyListenersOnReplication="true"/> 
          <Channel className="org.apache.catalina.tribes.group.GroupChannel"> 
            <Membership className="org.apache.catalina.tribes.membership.McastService" 
                        address="224.0.0.4" 
                        port="45564" 
                        frequency="500" 
                        dropTime="3000"/> 
            <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver" 
                      address="192.168.1.112"
                      port="4000"
                      autoBind="100" 
                      selectorTimeout="5000" 
                      maxThreads="6"/> 
            <Sender className="org.apache.catalina.tribes.transport.ReplicationTransmitter"> 
              <Transport className="org.apache.catalina.tribes.transport.nio.PooledParallelSender" /> 
            </Sender> 
            <Interceptor className="org.apache.catalina.tribes.group.interceptors.TcpFailureDetector"/> 
            <Interceptor className="org.apache.catalina.tribes.group.interceptors.MessageDispatch15Interceptor"/> 
         <Interceptor className="org.apache.catalina.tribes.group.interceptors.ThroughputInterceptor"/> 
          </Channel> 
          <Valve className="org.apache.catalina.ha.tcp.ReplicationValve" 
                 filter=""/> 
          <Valve className="org.apache.catalina.ha.session.JvmRouteBinderValve"/> 
          <ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/> 
          <ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/> 
        </Cluster>

server2

...

<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat2">
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster" 
                 channelSendOptions="8"> 
          <Manager className="org.apache.catalina.ha.session.DeltaManager" 
                   expireSessionsOnShutdown="false" 
                   notifyListenersOnReplication="true"/> 
          <Channel className="org.apache.catalina.tribes.group.GroupChannel"> 
            <Membership className="org.apache.catalina.tribes.membership.McastService" 
                        address="224.0.0.4" 
                        port="45564" 
                        frequency="500" 
                        dropTime="3000"/> 
            <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver" 
                      address="192.168.1.64"
                      port="4000"
                      autoBind="100" 
                      selectorTimeout="5000" 
                      maxThreads="6"/> 
            <Sender className="org.apache.catalina.tribes.transport.ReplicationTransmitter"> 
              <Transport className="org.apache.catalina.tribes.transport.nio.PooledParallelSender" /> 
            </Sender> 
            <Interceptor className="org.apache.catalina.tribes.group.interceptors.TcpFailureDetector"/> 
            <Interceptor className="org.apache.catalina.tribes.group.interceptors.MessageDispatch15Interceptor"/> 
         <Interceptor className="org.apache.catalina.tribes.group.interceptors.ThroughputInterceptor"/> 
          </Channel> 
          <Valve className="org.apache.catalina.ha.tcp.ReplicationValve" 
                 filter=""/> 
          <Valve className="org.apache.catalina.ha.session.JvmRouteBinderValve"/> 
          <ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/> 
          <ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/> 
        </Cluster>

...

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

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

<title>Insert title here</title>

</head>

<body>

<%=session.getId() %><br>
<%

String msg = (String)session.getAttribute("msg");

if(null == msg){

    session.setAttribute("msg", "Hello!");

}else{

    session.setAttribute("msg", msg + 0);

}

%>

<%=session.getAttribute("msg") %>

</body>

</html>

web.xml

<?xml version="1.0" encoding="UTF-8"?>

  <welcome-file-list>

      <welcome-file>index.jsp</welcome-file>

  </welcome-file-list>

  <distributable/>

</web-app>

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。