Apache+Tomcat配置负载均衡

由于集团开始实施个人任务管理模块，内部业务支撑平台的使用人数直线上升，每个月的月初在线人数达到顶峰，原有的一个Tomcat已经胜任不了，俺决定通过负载均衡来解决。

之前没搞过负载均衡，于是乎，在各大搜索网站搜索文档无数。从原理着手，先理解一下原理，有助于接下来的实施，然后再找找有哪些技术和方案，最后决定用Apache+Tomcat配置负载均衡来解决

接下来就开始在虚拟机上搞实验，俺的是笔记本，开两个虚拟机，卡得我想吐。喝了半怀咖啡，鼠标才给我动两下，伤不起呀。果断关掉一个虚拟机，决定在一个虚拟机内开两个Tomcat来测试：

1、首先需要下载相关的文件：

      Apache:   httpd-2.2.17-win32-x86-no_ssl.msi

      Tomcat:   apache-tomcat-6.0.35-windows-x86.zip

      模块     ： tomcat-connectors-1.2.37-windows-i386-httpd-2.2.x.zip

      JDK      :  jdk-6u10-rc2-bin-b32-windows-i586-p-12_sep_2008.exe

2、安装JDK文件，配置JDK环境

3、安装Apache服务器，按照网上查的资料，需要配置以下文件

    修改http.conf，在文件最后加上下面一句话就可以了：include "安装目录\Apache Software Foundation\Apache2.2\conf\mod_jk.conf"

    复制mod_jk.so到安装目录\Apache Software Foundation\Apache2.2\modules

    http.conf同目录下新建mod_jk.conf文件，内容如下：

    LoadModule jk_module modules/mod_jk.so
 
    JkWorkersFile conf/workers.properties
 
    #指定那些请求交给tomcat处理,"controller"为在workers.propertise里指定的负载分配控制器名
    JkMount /*.jsp controller

    在http.conf同目录下新建 workers.properties文件，内容如下   

     #server

      worker.list = controller

     #========tomcat1========

     worker.tomcat1.port=11009

     worker.tomcat1.host=localhost

     worker.tomcat1.type=ajp13

     worker.tomcat1.lbfactor = 1

    #========tomcat2========

     worker.tomcat2.port=12009

     worker.tomcat2.host=localhost

     worker.tomcat2.type=ajp13

     worker.tomcat2.lbfactor = 1

     #========tomcat3========

     #worker.tomcat3.port=13009

     #worker.tomcat3.host=192.168.0.80 //在我的虚拟机中的，可以算远程的吧   #worker.tomcat3.type=ajp13

     #worker.tomcat3.lbfactor = 1

     #========controller,负载均衡控制器========

     worker.controller.type=lb

     #worker.controller.balanced_workers=tomcat1,tomcat2,tomcat3 worker.controller.balanced_workers=tomcat1,tomcat2

     worker.controller.sticky_session=false   worker.controller.sticky_session_force=1   #worker.controller.sticky_session=1

4、安装Tomcat，并配置如下：

    修改SERVER.XML文件

    1）、<Connector port="11009" protocol="AJP/1.3" redirectPort="8443" /> 

    2）、 <Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat1">

    3）、<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster" channelSendOptions="8">  
      <!--    
            
          <Manager className="org.apache.catalina.ha.session.BackupManager" 
                    expireSessionsOnShutdown="false" 
                    notifyListenersOnReplication="true" 
                    mapSendOptions="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="228.0.0.4" 
                        port="45564" 
                        frequency="500" 
                        dropTime="3000"/>  
            <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
                       address="localhost" 
                      port="4000" 
                      autoBind="100" 
                      selectorTimeout="5000" 
                      maxThreads="6"/>  
            <!-- timeout="60000"-->  
            <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"/> 
  
          <Deployer className="org.apache.catalina.ha.deploy.FarmWarDeployer" 
                    tempDir="/tmp/war-temp/" 
                    deployDir="/tmp/war-deploy/" 
                    watchDir="/tmp/war-listen/" 
                    watchEnabled="false"/>  
 
          <ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/> 
           <ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/> 
      </Cluster>

编写测试页面test2.jsp

<%@ page contentType="text/html; charset=GBK" %>
 
<%@ page import="java.util.*" %>
 
<html><head><title>Cluster App Test</title></head>
 
<body>
 
Server Info:
 
<%
 
out.println(request.getLocalAddr() + " : " + request.getLocalPort()+"<br>");%>
 
<%
 
  out.println("<br> ID " + session.getId()+"<br>");
 
  // 如果有新的 Session 属性设置
 
  String dataName = request.getParameter("dataName");
 
  if (dataName != null && dataName.length() > 0) {
 
     String dataValue = request.getParameter("dataValue");
 
     session.setAttribute(dataName, dataValue);
 
  }
 
  out.println("<b>Session 列表</b><br>");
 
  System.out.println("============================");
 
  Enumeration e = session.getAttributeNames();
 
  while (e.hasMoreElements()) {
 
     String name = (String)e.nextElement();
 
     String value = session.getAttribute(name).toString();
 
     out.println( name + " = " + value+"<br>");
 
         System.out.println( name + " = " + value);
 
   }
 
%>
 
  <form action="test2.jsp" method="POST">
 
    名称:<input type=text size=20 name="dataName">
 
     <br>
 
    值:<input type=text size=20 name="dataValue">
 
     <br>
 
    <input type=submit>
 
   </form>
 
</body>
 
</html>

修改项目下面的web.xml,加入<distributable/>

测试成功，Session同步复制