tomcat6集群 推荐

tomcat集群安装
软件及环境:
apache-tomcat-6.0.29
nginx-0.8.15
centos5.5
nginx:192.168.1.251
tomat1:192.168.1.251
tomat2:192.168.1.252
tomcat安装目录为:/usr/local/tomcat
nginx安装目录为:/usr/local/nginx

jdk、tomcat、nginx安装过程省略！

Tomcat1配置如下:
修改<Engine name="Catalina" defaultHost="localhost">为
<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat1">
在Engine字段中添加下cluster内容：
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"
channelSendOptions="6" defaultMode="true">

<!-- <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"
address="228.0.0.2" <!—组播地址-->
bind="192.168.1.251" <!—绑定本机的IP-->
port="45564" <!—通信端口-->
frequency="500"
dropTime="3000"/>
<Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
address="192.168.1.251"
autoBind="100"
port="5001"
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;"/>

<!-- <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.ClusterSessionListener"/>
</Cluster>

Tomcat2配置如下:
修改<Engine name="Catalina" defaultHost="localhost">为:
<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat2">
在Engine字段中添加下cluster内容：
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"
channelSendOptions="6" defaultMode="true">

<!-- <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"
address="228.0.0.2"
bind="192.168.1.252"
port="45564"
frequency="500"
dropTime="3000"/>
<Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
address="192.168.1.252"
autoBind="100"
port="5002"
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;"/>

<!-- <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.ClusterSessionListener"/>
</Cluster>

配置nginx负载：
使用nginx做负载很简单，只要在配置文件里面加
upstream www.tomcat.com {
# ip_hash; //启用这个的话，整个C类地址会防问同一个server
server 192.168.1.251:8080;
server 192.168.1.252:8080;
#两台负载的IP地址，这里默认的是RR
}

server
{
listen 80;
server_name _;

location / {
proxy_pass http://www.tomcat.com; proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}

}

到这里配置文件就OK了，服务器的启动顺序如下:

|-------------| |-------------| |-------------|
|tomcat1 | --à |tomcat2 | --à |nginx |
|-------------| |-------------| |-------------|

先启动tocmat1,等tomcat1启动完全的时候再启动tomcat2，等两个tocmat全启动之后，再启动nginx

测试一下我们的配置,测试页如下:
<%@ page contentType="text/html; charset=GBK" %>
<%@ page import="java.util.*" %>
<html><head><title>Cluster Test</title></head>
<body>
<%
//HttpSession session = request.getSession(true);
System.out.println(session.getId());
out.println("<br> SESSION ID:" + session.getId()+"<br>");
// 如果有新的请求，则添加session属性
String name = request.getParameter("name");
if (name != null && name.length() > 0) {
String value = request.getParameter("value");
session.setAttribute(name, value);
}
out.print("<b>Session List:</b>");
Enumeration<String> names = session.getAttributeNames();
while (names.hasMoreElements()) {
String sname = names.nextElement();
String value = session.getAttribute(sname).toString();
out.println( sname + " = " + value+"<br>");
System.out.println( sname + " = " + value);
}
%>
<form action="index.jsp" method="post">
名称:<input type=text size=20 name="name">
<br>
值:<input type=text size=20 name="value">
<br>
<input type=submit value="提交">
</form>
</body>
</html>

配置WEB-INF下的web.xml文件，在<web-app>中加入<distributable/>

<web-app>

<distributable/>

</web-app>

然后我们就可以用nginx来防问了！
先防问，然后随便关闭那一个，再开启，发现SESSION都是同步的！

PS:
负载的时候可以用APACHE或NGINX，如果什么都不用，两台一接防问了话，可能会出错极session不同步的问题，网上也很多人介意不要做seeeion同步，这样会降低机器的性能，有一个方法可以，就是NGINX的ip_hash,这样至少可以保证客户端去防问同一台TOCMAT，除非那台TOCMAT挂了！