（转）Apache2 + Tomcat6配置负载均衡

 
1. 安装Apache和Tomcat，这里假定Apache2.2.3，Tomcat6.x；且Apache安装在apachehost，tomcat分别安装在tomcathost1和tomcathost2上；
2. 修改/etc/hosts文件，确定以下行没有被注释掉
view plaincopy to clipboardprint?
LoadModule proxy_module modules/mod_proxy.so  
LoadModule proxy_http_module modules/mod_proxy_http.so  
LoadModule proxy_ajp_module modules/mod_proxy_ajp.so 
  LoadModule proxy_module modules/mod_proxy.so
  LoadModule proxy_http_module modules/mod_proxy_http.so
  LoadModule proxy_ajp_module modules/mod_proxy_ajp.so
3. 修改/etc/hosts文件，添加以下行：
view plaincopy to clipboardprint?
ProxyRequests off  
<Proxy balancer://tccluster> 
    BalancerMember http://tomcathost1:8080 loadfactor=2 max=150 smax=145 
    BalancerMember http://tomcathost2:8080 loadfactor=1 max=150 smax=145 
    Order Deny,Allow  
    Allow from all  
</Proxy> 
<Location /balancer-manager> 
    SetHandler balancer-manager  
    Order Deny,Allow  
    Allow from all  
</Location> 
<Location /examples> 
    ProxyPass balancer://tccluster/examples stickysession=jsessionid 
    ProxyPassReverse balancer://tccluster/examples  
    Order Deny,Allow  
    Allow from all  
</Location> 
  ProxyRequests off
  <Proxy balancer://tccluster>
      BalancerMember http://tomcathost1:8080 loadfactor=2 max=150 smax=145
      BalancerMember http://tomcathost2:8080 loadfactor=1 max=150 smax=145
      Order Deny,Allow
      Allow from all
  </Proxy>
  <Location /balancer-manager>
      SetHandler balancer-manager
      Order Deny,Allow
      Allow from all
  </Location>
  <Location /examples>
      ProxyPass balancer://tccluster/examples stickysession=jsessionid
      ProxyPassReverse balancer://tccluster/examples
      Order Deny,Allow
      Allow from all
  </Location>
4. 确定apachehost和两台tomcathost可以互访，并且两个tomcat机器在一个网段内；
5. 确定两台tomcat host多播已经打开，在Linux机器上可以使用cat /proc/net/dev_mcast检查，如果文件存在基本上就是打开了；另外确定两台tomcat机器的/etc/hosts文件中包含“xxx.xxx.xxx.xxx    hostname”比如“172.17.1.101    tomcathost1”或“172.17.1.102    tomcathost2”；
6. 修改两个tomcat的conf/server.xml文件，对Engine节点分别添加jvmRoute="tomcat1"和jvmRoute="tomcat2"，并添加以下内容：
view plaincopy to clipboardprint?
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"   
    channelSendOptions="6"> 
      
      
    <Manager className="org.apache.catalina.ha.session.DeltaManager" 
        expireSessionsOnShutdown="false" 
        notifyListenersOnReplication="true"/> 
    <!--  
    <Manager className="org.apache.catalina.ha.session.BackupManager" 
        expireSessionsOnShutdown="false" 
        notifyListenersOnReplication="true" 
        mapSendOptions="6"/> 
    --> 
    <Channel className="org.apache.catalina.tribes.group.GroupChannel"> 
        <Membership className="org.apache.catalina.tribes.membership.McastService" 
            address="228.0.0.5" 
            port="45564" 
            frequency="500" 
            dropTime="3000"/> 
        <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver" 
            address="auto" 
            port="4000" 
            selectorTimeout="100" 
            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"/> 
    </Channel> 
    <Valve className="org.apache.catalina.ha.tcp.ReplicationValve" filter=".*\.gif;.*\.js;.*\.jpg;.*\.png;.*\.htm;.*\.html;.*\.css;.*\.txt;"/> 
      
    <ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/> 
    <ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/> 
</Cluster> 
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"
    channelSendOptions="6">
   
   
    <Manager className="org.apache.catalina.ha.session.DeltaManager"
        expireSessionsOnShutdown="false"
        notifyListenersOnReplication="true"/>
    <!--
    <Manager className="org.apache.catalina.ha.session.BackupManager"
        expireSessionsOnShutdown="false"
        notifyListenersOnReplication="true"
        mapSendOptions="6"/>
    -->
    <Channel className="org.apache.catalina.tribes.group.GroupChannel">
        <Membership className="org.apache.catalina.tribes.membership.McastService"
            address="228.0.0.5"
            port="45564"
            frequency="500"
            dropTime="3000"/>
        <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
            address="auto"
            port="4000"
            selectorTimeout="100"
            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"/>
    </Channel>
    <Valve className="org.apache.catalina.ha.tcp.ReplicationValve" filter=".*\.gif;.*\.js;.*\.jpg;.*\.png;.*\.htm;.*\.html;.*\.css;.*\.txt;"/>
   
    <ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/>
    <ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/>
</Cluster>
7. 创建一个web app，这里为了简单使用tomcat自带的examples web app（webapps/examples)，修改其中的WEB-INF/web.xml文件，在其中<display-name>Servlet and JSP Examples</display-name>节点后添加<distributable/>表明此应用与集群服务器复制Session；
8. 在两个Tomcat的webapps/examples目录下各创建一个test.jsp文件，用来测试Cluster中两个Tomcat的Session复制，代码如下：
view plaincopy to clipboardprint?
<html> 
<head> 
    <title></title> 
</head> 
<body> 
<%  
    String mydata = request.getParameter("mydata");  
    if (mydata != null && mydata.length() != 0) {  
        session.setAttribute("mydata", mydata);  
    }  
      
    out.println("request.getLocalAddr(): " + request.getLocalAddr());  
    out.println("<br/>");  
    out.println("request.getLocalPort(): " + request.getLocalPort());  
    out.println("<br/>");  
    out.println("Session ID: " + session.getId());  
    out.println("<br/>");  
      
    out.println("mydata: " + session.getAttribute("mydata"));  
%> 
<form> 
    <input type=text size=20 name="mydata"> 
    <br> 
    <input type=submit> 
</form> 
</body> 
</html> 
<html>
<head>
    <title></title>
</head>
<body>
<%
    String mydata = request.getParameter("mydata");
    if (mydata != null && mydata.length() != 0) {
        session.setAttribute("mydata", mydata);
    }
   
    out.println("request.getLocalAddr(): " + request.getLocalAddr());
    out.println("<br/>");
    out.println("request.getLocalPort(): " + request.getLocalPort());
    out.println("<br/>");
    out.println("Session ID: " + session.getId());
    out.println("<br/>");
   
    out.println("mydata: " + session.getAttribute("mydata"));
%>
<form>
    <input type=text size=20 name="mydata">
    <br>
    <input type=submit>
</form>
</body>
</html>
9. 启动Tomcat和Apache，访问http://apachehost/examples/，可以修改其中Session中的值，并且可以看到两个tomcat的Session中的值是一样的；
10. 访问http://apachehost/balancer-manager，可以使用此负载均衡管理页面来动态enable/disable其中的某个tomcat。