Apache2.2.11+Tomcat6.0.20集群配置

Apache2.x和Tomcat配置可以采用反向代理的方式(mod proxy)，也可以采用JK模块，最终采用了JK模块，JK模块的效率要比反向代理高，这是Apache官方网站上说的，我没有测试过。JK配置虽然复杂，但更加灵活。
首先，下载Apache2.2.11，Tomcat6.0.20解压版，以及mod_jk-1.2.28-httpd-2.2.3.so
安装Apache服务器，将mod_jk-1.2.28-httpd-2.2.3.so重命名为mod_jk.so并拷贝到Apache安装目录下的modules文件夹中。
在Apache2.2安装目录的conf文件夹下，建立以下3个文件：
mod_jk.conf、workers.properties、uriworkermap.properties
在httpd.conf最后加上：

# JK module settings
Include conf/mod_jk.conf

# JK module settings Include conf/mod_jk.conf

表示将mod_jk.conf配置文件包含进来，以下是mod_jk.conf文件的内容：

# Load JK Module
LoadModule jk_module modules/mod_jk.so

# Configure mod_jk
JkWorkersFile conf/workers.properties
JkMountFile conf/uriworkermap.properties
JkShmFile logs/mod_jk.shm
JkLogFile logs/mod_jk.log
JkOptions +ForwardKeySize +ForwardURICompat -ForwardDirectories
JkLogLevel warn
JkLogStampFormat "[%a %b %d %H:%M:%S %Y]"
HostnameLookups Off

<Location /jkmanager/>
    JkMount jkstatus
    Order deny,allow
    Deny from all
    Allow from 127.0.0.1
</Location>

# Load JK Module LoadModule jk_module modules/mod_jk.so  # Configure mod_jk JkWorkersFile conf/workers.properties JkMountFile conf/uriworkermap.properties JkShmFile logs/mod_jk.shm JkLogFile logs/mod_jk.log JkOptions +ForwardKeySize +ForwardURICompat -ForwardDirectories JkLogLevel warn JkLogStampFormat "[%a %b %d %H:%M:%S %Y]" HostnameLookups Off  <Location /jkmanager/>     JkMount jkstatus     Order deny,allow     Deny from all     Allow from 127.0.0.1 </Location>

 接下来配置workers.properties文件：

# environment slash for Windows(反斜杠代表Windows系统)
ps=\

worker.retries=3

# 此处定义了一个负载均衡器和状态监视器
worker.list=loadbalancer,jkstatus

worker.tomcatA.type=ajp13
worker.tomcatA.host=localhost
worker.tomcatA.port=9001
worker.tomcatA.lbfactor=1
worker.tomcatA.connection_pool_timeout=600
worker.tomcatA.socket_keepalive=true
worker.tomcatA.socket_timeout=60

worker.tomcatB.type=ajp13
worker.tomcatB.host=localhost
worker.tomcatB.port=9002
worker.tomcatB.lbfactor=1
worker.tomcatB.connection_pool_timeout=600
worker.tomcatB.socket_keepalive=true
worker.tomcatB.socket_timeout=60

worker.tomcatC.type=ajp13
worker.tomcatC.host=localhost
worker.tomcatC.port=9003
worker.tomcatC.lbfactor=1
worker.tomcatC.connection_pool_timeout=600
worker.tomcatC.socket_keepalive=true
worker.tomcatC.socket_timeout=60

worker.jkstatus.type=status

worker.loadbalancer.type=lb
worker.loadbalancer.sticky_session=true
worker.loadbalancer.sticky_session_force=false
worker.loadbalancer.balance_workers=tomcatA,tomcatB,tomcatC

# environment slash for Windows(反斜杠代表Windows系统) ps=\  worker.retries=3  # 此处定义了一个负载均衡器和状态监视器 worker.list=loadbalancer,jkstatus  worker.tomcatA.type=ajp13 worker.tomcatA.host=localhost worker.tomcatA.port=9001 worker.tomcatA.lbfactor=1 worker.tomcatA.connection_pool_timeout=600 worker.tomcatA.socket_keepalive=true worker.tomcatA.socket_timeout=60  worker.tomcatB.type=ajp13 worker.tomcatB.host=localhost worker.tomcatB.port=9002 worker.tomcatB.lbfactor=1 worker.tomcatB.connection_pool_timeout=600 worker.tomcatB.socket_keepalive=true worker.tomcatB.socket_timeout=60  worker.tomcatC.type=ajp13 worker.tomcatC.host=localhost worker.tomcatC.port=9003 worker.tomcatC.lbfactor=1 worker.tomcatC.connection_pool_timeout=600 worker.tomcatC.socket_keepalive=true worker.tomcatC.socket_timeout=60  worker.jkstatus.type=status  worker.loadbalancer.type=lb worker.loadbalancer.sticky_session=true worker.loadbalancer.sticky_session_force=false worker.loadbalancer.balance_workers=tomcatA,tomcatB,tomcatC

上述配置文件中，sticky_session=true，sticky_session_force=false。很多文章建议，前者设置为true时，后者也设置为true。

实际上，负载均衡和集群复制是两个概念。在Tomcat的集群复制中，分为DeltaManager和BackupManager两种，前者适合于小型系统，任何情况下，均进行Session复制，消耗大量资源。所以，我们应该采用BackupManager，仅在需要的时候(Tomcat挂掉的时候)进行Session复制。

sticky_session=true表示某个请求始终由当前Tomcat处理，不会转移到其他Tomcat上。sticky_session_force=false表示，当前Tomcat挂掉的时候，自动将Session复制到其他Tomcat上。如果将sticky_session_force设置为true，当你关闭一台Tomcat并刷新网页，将得到503错误。但设置为false，关闭一台Tomcat并刷新网页，被关闭的那台Tomcat上的Session会被自动复制到其他Tomcat上，系统继续正常运行。

再来看uriworkermap.properties文件，这个文件是用来定义哪些资源由Tomcat处理，哪些资源由Apache处理。

/*.jsp=loadbalancer
/*.action=loadbalancer
/jkmanager/*=jkstatus

!*.gif=loadbalancer
!*.jpg=loadbalancer
!*.png=loadbalancer
!*.bmp=loadbalancer
!*.css=loadbalancer
!*.js=loadbalancer
!*.htm=loadbalancer
!*.html=loadbalancer
!*.swf=loadbalancer

/*.jsp=loadbalancer /*.action=loadbalancer /jkmanager/*=jkstatus  !*.gif=loadbalancer !*.jpg=loadbalancer !*.png=loadbalancer !*.bmp=loadbalancer !*.css=loadbalancer !*.js=loadbalancer !*.htm=loadbalancer !*.html=loadbalancer !*.swf=loadbalancer

上述配置文件将jsp和action交给负载均衡器处理，实际上就是Tomcat，其他请求由Apache处理。如果你用!/*.gif=loadbalancer，图片可能会不显示，正确设置虚拟目录即可。或者使用!*.gif=loadbalancer，代表所有gif图片均交给Apache处理。

 

接下来，配置Tomcat的配置文件。Tomcat6解压后，server.xml和Tomcat5相比，少很多注释的内容，所以需要到Tomcat5的server.xml文件中拷贝过来，然后去掉注释。

需要修改的端口：

SHUTDOWN、HTTP/1.1、AJP/1.3、Receiver 4001，如果是同一台机器，确保上述端口均不同。

3台Tomcat的jvmRoute需要同workers.properties中的一致

<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcatA">
<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcatB">
<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcatC">

<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcatA"> <Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcatB"> <Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcatC">

 以下是集群配置内容(Tomcat6的server.xml中没有相应的注释代码，必须从Tomcat5的里面复制过来，再修改一下)：

<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"
               channelSendOptions="6">

        <Manager className="org.apache.catalina.ha.session.BackupManager"
                 expireSessionsOnShutdown="false"
                 notifyListenersOnReplication="true"
                 mapSendOptions="6"/>
        <!--
        <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"
                      bind="127.0.0.1"
                      address="228.0.0.4"
                      port="45564"
                      frequency="500"
                      dropTime="3000"/>
          <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
                    address="127.0.0.1"
                    port="4001"
                    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"/>
          <Interceptor className="org.apache.catalina.tribes.group.interceptors.ThroughputInterceptor"/>
        </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.ClusterSessionListener"/>
      </Cluster>

<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"                channelSendOptions="6">          <Manager className="org.apache.catalina.ha.session.BackupManager"                  expireSessionsOnShutdown="false"                  notifyListenersOnReplication="true"                  mapSendOptions="6"/>         <!--         <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"                       bind="127.0.0.1"                       address="228.0.0.4"                       port="45564"                       frequency="500"                       dropTime="3000"/>           <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"                     address="127.0.0.1"                     port="4001"                     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"/>           <Interceptor className="org.apache.catalina.tribes.group.interceptors.ThroughputInterceptor"/>         </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.ClusterSessionListener"/>       </Cluster>

注意：这里要使用BackupManager，不要使用DeltaManager。3台Tomcat的Receiver端口要设置为不一样的。

接下来，要进行Session复制，还需要给你的web.xml配置文件中加一行<distributable/>。这样很麻烦，改变Tomcat的content.xml配置文件就可以了，修改19行为<Context distributable="true">

大功告成，先启动Apache，然后分别启动几个Tomcat。

在浏览器上输入http://localhost/test.jsp

在一个Tomcat设置Session的内容，然后刷新，通过观察后台窗口，会发现Session一直粘在这台Tomcat上，然后关闭掉这台Tomcat，继续刷新页面，会发现Session里面的内容自动转移到了另外一台Tomcat上面。如果你将sticky_session_force设置为false，此时刷新页面，就会报503错误。

对uriworkermap.properties还有一些模糊，加了/后就代表相对路径，不加代表绝对匹配，我用*.jsp，居然报404找不到页面的错误。用/*.jsp就正常了，我没有设置任何虚拟目录。而图片的配置刚好相反，加了斜杠就不显示，去掉就可以显示了。想不通啊！

以下是测试用的test.jsp

<%@ page contentType="text/html; charset=GBK" %>
<%@ page import="java.util.*" %>
<html><head><title>Cluster App Test</title></head>
<body>
<%
    System.out.println("SessionID:"  + session.getId());
%>
Server Info:
<%
out.println(request.getServerName() + " : " + request.getServerPort()+"<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.print("<b>Session 列表</b><br>");
   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="test.jsp" method="POST">
     名称:<input type=text size=20 name="dataName">
     <br>
     数值:<input type=text size=20 name="dataValue">
     <br>
    <input type=submit>
  </form>
</body>
</html>

摘自：http://hi.baidu.com/coolda/blog/item/db40e4111914bccaa6ef3fc1.html