apache + tomcat 集群 负载均衡 session 同步

1. 在apache安装目录/conf/httpd.conf 结尾加上

include conf\mod_jk.conf

2. 将mod_jk-1.2.27-httpd-2.2.10.so复制到modules下

3. 在conf目录新建文件mod_jk.conf

增加内容

LoadModule jk_module modules/mod_jk-1.2.27-httpd-2.2.10.so

JkWorkersFile conf/workers.properties

JkLogFile logs/mod_jk.log

JkLogLevel error

#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

JkMount /*.do controller

JkMountCopy all #详细见下面说明

注意：使用mod_jk 1.2.6+时，如果你希望声明一个全局的JkMount's或者JkMountFile's来代替每个虚拟主机，你需要引入’JkMountCopy all’作为全局变量。如果你不想为每个虚拟主机拷贝同样的JkMount/MkMountFile,你需要在虚拟主机指令中声明’JkMountCopy On’。如果不加入此项，则负载均衡会失败！

4. 在conf目录下增加workers.properties

内容为

#server

worker.list = controller,tomcat1,tomcat2 #server 列表

#========tomcat1========

worker.tomcat1.port=8009 #ajp13 端口号，在tomcat下server.xml配置,默认8009

worker.tomcat1.host=localhost #tomcat的主机地址，如不为本机，请填写ip地址

worker.tomcat1.type=ajp13

worker.tomcat1.lbfactor = 1 #server的加权比重，值越高，分得的请求越多

#========tomcat2========

worker.tomcat2.port=8010 #ajp13 端口号，在tomcat下server.xml配置,默认8009

worker.tomcat2.host=localhost #tomcat的主机地址，如不为本机，请填写ip地址

worker.tomcat2.type=ajp13

worker.tomcat2.lbfactor = 1 #server的加权比重，值越高，分得的请求越多

#========controller,负载均衡控制器========

worker.controller.type=lb

worker.controller.balanced_workers=tomcat1,tomcat2 #指定分担请求的tomcat

worker.controller.sticky_session=false

worker.controller.sticky_session_force=true

说明:worker.controller.sticky_session，设置为1或true使用粘着session，设置为0或false不使用粘着session。如果sticky_session设为true时，建议sticky_session_force设为false，此参数表明如果集群中某台服务器在多次请求没有响应后，将转发当前的请求到其它服务器上处理；sticky_session=false时，影响比较大，会导致转发到其它服务器上的请求，找不到原来的session，所以如果此时请求中有读取session中某些信息的话，就会导致应用的null异常。sticky_session、sticky_session_force的默认值分别为true，false。

sticky_session sticky_session_force 含义

true false SESSION会复制，有粘性

true true SESSION不复制，有粘性

false false SESSION会复制，无粘性

false true SESSION会复制，无粘性

如果应用在同一台主机上需作下列修改

5.修改 <Server port="8005" shutdown="SHUTDOWN"> 为 <Server port="8006" shutdown="SHUTDOWN">

6. <Connector port="8080" maxHttpHeaderSize="8192"

maxThreads="150" minSpareThreads="25" maxSpareThreads="75"

enableLookups="false" redirectPort="8443" acceptCount="100"

connectionTimeout="20000" disableUploadTimeout="true" />

改为

<Connector port="8081" maxHttpHeaderSize="8192"

maxThreads="150" minSpareThreads="25" maxSpareThreads="75"

enableLookups="false" redirectPort="8443" acceptCount="100"

connectionTimeout="20000" disableUploadTimeout="true" />

7. <Connector port="8009"

enableLookups="false" redirectPort="8443" protocol="AJP/1.3" />

改为

<Connector port="8010"

enableLookups="false" redirectPort="8443" protocol="AJP/1.3" />

至此 实现了负载均衡.

集群: 实现session 同步

8.

修改tomcat server.xml

<!-- You should set jvmRoute to support load-balancing via AJP ie : -->

<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat1">

<!-- Define the top level container in our container hierarchy

<Engine name="Catalina" defaultHost="localhost">

-->

9.

修改tomcat server.xml

<Cluster 注释去掉

修改端口为 4002

<Receiver

className="org.apache.catalina.cluster.tcp.ReplicationListener"

tcpListenAddress="auto"

tcpListenPort="4001"

tcpSelectorTimeout="100"

tcpThreadCount="6"/>

改为

<Receiver

className="org.apache.catalina.cluster.tcp.ReplicationListener"

tcpListenAddress="auto"

tcpListenPort="4001"

tcpSelectorTimeout="100"

tcpThreadCount="6"/>

10. 修改tomcat server.xml

去掉注释 改端口为 8083

<Connector port="8082"

maxThreads="150" minSpareThreads="25" maxSpareThreads="75"

enableLookups="false" acceptCount="100" connectionTimeout="20000"

proxyPort="80" disableUploadTimeout="true" />

改为

<Connector port="8083"

maxThreads="150" minSpareThreads="25" maxSpareThreads="75"

enableLookups="false" acceptCount="100" connectionTimeout="20000"

proxyPort="80" disableUploadTimeout="true" />

11. 应用web.xml

增加 <distributable/>

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.4"

xmlns="http://java.sun.com/xml/ns/j2ee"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>TomcatDemo</display-name>

<distributable/>

<welcome-file-list>

<welcome-file>index.jsp</welcome-file>

</welcome-file-list>

</web-app>

即可实现集群及负载均衡

测试界面:

<%@ page contentType="text/html; charset=GBK" %>

<%@ page import="java.util.*" %>

<html>

<body>

Server Info:

<%

out.println(request.getLocalAddr() + " : " + request.getLocalPort());%>

<%

out.println("ID " + session.getId());

// 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("Session列表");

Enumeration e = session.getAttributeNames();

while (e.hasMoreElements()) {

String name = (String)e.nextElement();

String value = session.getAttribute(name).toString();

out.println( name + " = " + value);

System.out.println( name + " = " + value);

}

%>

<form action="index.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>