配置環境需要：1.Apache服務器，下載地址：http://httpd.apache.org/download.cgi#apache22
2.tomcat6.0或者tomcat7.0，（集羣中tomcat不能既有tomcat6又有tomcat7，否則雖能夠負載均衡，但不能進行session複製，下載地址：http://tomcat.apache.org/
3.jk是tomcat提供給http服務器的插件mod_jk-1.2.31-httpd-2.2.3.so 下載地址：http://archive.apache.org/dist/tomcat/tomcat-connectors/jk/binaries/win32/jk-1.2.31/
修改Apache配置
1、修改httpd.conf
我的Apache安裝在D:\Program Files\Apache Software Foundation\Apache2.2，找到conf目錄下的httpd.conf，在文件的最後一行添加
include "D:\Program Files\Apache Software Foundation\Apache2.2\conf\mod_jk.conf"
2、新建mod_jk.conf文件，內容如下：
#加載mod_jk ModuleLoadModule jk_module modules/mod_jk-1.2.31-httpd-2.2.3.so
#指定workers.properties文件路徑
JkWorkersFile conf/workers.properties
#指定那些請求交給tomcat處理,"controller"爲在workers.propertise裏指定的負載分配控制器名
JkMount /*.jsp controller
3、將下載的JK插件mod_jk-1.2.31-httpd-2.2.3.so複製到Apache安裝目錄的modules目錄下。
4、新建並編輯workers.properties文件，內容如下：
worker.list = controller
#========tomcat1========worker.tomcat1.port=11009 #ajp13 端口號，在tomcat下server.xml配置,默認8009
worker.tomcat1.host=localhost #tomcat的主機地址，如不爲本機，請填寫ip地址
worker.tomcat1.type=ajp13
worker.tomcat1.lbfactor = 1 #server的加權比重，值越高，分得的請求越多
#========tomcat2========
worker.tomcat2.port=12009 #ajp13 端口號，在tomcat下server.xml配置,默認8009
worker.tomcat2.host=localhost #tomcat的主機地址，如不爲本機，請填寫ip地址
worker.tomcat2.type=ajp13
worker.tomcat2.lbfactor = 1 #server的加權比重，值越高，分得的請求越多
#========tomcat3========
worker.tomcat3.port=8009 #ajp13 端口號，在tomcat下server.xml配置,默認8009
worker.tomcat3.host=localhost #tomcat的主機地址，如不爲本機，請填寫ip地址
worker.tomcat3.type=ajp13
worker.tomcat3.lbfactor = 1 #server的加權比重，值越高，分得的請求越多
#========controller,負載均衡控制器========
worker.controller.type=lb
worker.controller.balanced_workers=tomcat1,tomcat2,tomcat3
worker.controller.sticky_session=false（false指的是實現session複製）
這裏可以配置任意多個Tomcat，此處配置了3個Tomat服務器，所以爲了它們都能夠順利啓動起來，本地的服務器端口都是不同的，如果Tomcat不再同一機器上，沒必要改端口的。下面是tomcat1的server.xml的配置
<?xml version='1.0' encoding='utf-8'?>
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- Note: A "Server" is not itself a "Container", so you may not
define subcomponents such as "Valves" at this level.
Documentation at /docs/config/server.html
-->
<Server port="8001" shutdown="SHUTDOWN">
<!--APR library loader. Documentation at /docs/apr.html -->
<Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />
<!--Initialize Jasper prior to webapps are loaded. Documentation at /docs/jasper-howto.html -->
<Listener className="org.apache.catalina.core.JasperListener" />
<!-- Prevent memory leaks due to use of particular java/javax APIs-->
<Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
<!-- JMX Support for the Tomcat server. Documentation at /docs/non-existent.html -->
<Listener className="org.apache.catalina.mbeans.ServerLifecycleListener" />
<Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
<!-- Global JNDI resources
Documentation at /docs/jndi-resources-howto.html
-->
<GlobalNamingResources>
<!-- Editable user database that can also be used by
UserDatabaseRealm to authenticate users
-->
<Resource name="UserDatabase" auth="Container"
type="org.apache.catalina.UserDatabase"
description="User database that can be updated and saved"
factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
pathname="conf/tomcat-users.xml" />
</GlobalNamingResources>
<!-- A "Service" is a collection of one or more "Connectors" that share
a single "Container" Note: A "Service" is not itself a "Container",
so you may not define subcomponents such as "Valves" at this level.
Documentation at /docs/config/service.html
-->
<Service name="Catalina">
<!--The connectors can use a shared executor, you can define one or more named thread pools-->
<!--
<Executor name="tomcatThreadPool" namePrefix="catalina-exec-"
maxThreads="150" minSpareThreads="4"/>
-->
<!-- A "Connector" represents an endpoint by which requests are received
and responses are returned. Documentation at :
Java HTTP Connector: /docs/config/http.html (blocking & non-blocking)
Java AJP Connector: /docs/config/ajp.html
APR (HTTP/AJP) Connector: /docs/apr.html
Define a non-SSL HTTP/1.1 Connector on port 8080
-->
<Connector port="8081" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
<!-- A "Connector" using the shared thread pool-->
<!--
<Connector executor="tomcatThreadPool"
port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
-->
<!-- Define a SSL HTTP/1.1 Connector on port 8443
This connector uses the JSSE configuration, when using APR, the
connector should be using the OpenSSL style configuration
described in the APR documentation -->
<!--
<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
maxThreads="150" scheme="https" secure="true"
clientAuth="false" sslProtocol="TLS" />
-->
<!-- Define an AJP 1.3 Connector on port 8009 -->
<Connector port="11009" protocol="AJP/1.3" redirectPort="8443" />
<!-- An Engine represents the entry point (within Catalina) that processes
every request. The Engine implementation for Tomcat stand alone
analyzes the HTTP headers included with the request, and passes them
on to the appropriate Host (virtual host).
Documentation at /docs/config/engine.html -->
<!-- You should set jvmRoute to support load-balancing via AJP ie :
<Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1">
-->
<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat1">
<!--For clustering, please take a look at documentation at:
/docs/cluster-howto.html (simple how to)
/docs/config/cluster.html (reference documentation) -->
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
<!-- <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="auto"
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"/>
<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> -->
<!-- The request dumper valve dumps useful debugging information about
the request and response data received and sent by Tomcat.
Documentation at: /docs/config/valve.html -->
<!--
<Valve className="org.apache.catalina.valves.RequestDumperValve"/>
-->
<!-- This Realm uses the UserDatabase configured in the global JNDI
resources under the key "UserDatabase". Any edits
that are performed against this UserDatabase are immediately
available for use by the Realm. -->
<Realm className="org.apache.catalina.realm.UserDatabaseRealm"
resourceName="UserDatabase"/>
<!-- Define the default virtual host
Note: XML Schema validation will not work with Xerces 2.2.
-->
<Host name="localhost" appBase="webapps"
unpackWARs="true" autoDeploy="true"
xmlValidation="false" xmlNamespaceAware="false">
<!-- SingleSignOn valve, share authentication between web applications
Documentation at: /docs/config/valve.html -->
<!--
<Valve className="org.apache.catalina.authenticator.SingleSignOn" />
-->
<!-- Access log processes all example.
Documentation at: /docs/config/valve.html -->
<!--
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
prefix="localhost_access_log." suffix=".txt" pattern="common" resolveHosts="false"/>
-->
</Host>
</Engine>
</Service>
</Server>
注意：AJP13的connector的port和jvmRoute名稱和workers.properties中配置對應。
測試
建立測試項目
建立test項目，把這個項目分別部署到三個tomcat服務器下面，同時需要在項目的WEB-INF文件夾下的web.xml中添加<distributable/>這個標籤
建立test2.jsp，內容如下：
<%@ 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 屬性設置
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">
名稱:<input type=text size=20 name="dataName">
<br>
值:<input type=text size=20 name="dataValue">
<br>
<input type=submit>
</form>
</body>
</html>Session測試
將項目部署到3個服務器之後，然後分別啓動Apache和3個Tocmat服務器，這些Tomcat啓動順序隨意，然後打開http://localhost/test/test2.jsp，
按F5每刷新一次頁面，session的ID都是一樣的說明實現了session的複製，這樣就大功告成了！
截圖如下：
