tomcat的负载均衡问题

我采用了tomcat文档里面的第三种方法，用filter实现redirect。但是现在碰到一个问题，普通访问页面的跳转是没有问题的。一旦我需要向某个连接传递一个object，那么一旦跳转到其他服务器的连接，这个object就丢失了。

请问这个问题有什么好的解决办法吗。

是什么Object, 是保存在session中的么, 这个object有没有被复制呢/?

希望我这片文章对你有帮助
http://spaces.msn.com/dengyin2000/blog/cns!AF4AB52B167D7EE7!178.entry?_c11_blogpart_blogpart=blogview&_c=blogpart#permalink

谢谢楼上，
object是序列化后通过request传的，什么object其实不重要。我其实也是看了onjava上的这两篇文章来配置的。
我查看了filter的源码，其实就是发现某个rules匹配就redirect到另外一台服务器了。这样原来request里面的东西就丢失了。

我希望负载均衡能够把原来request里面的东西原原本本的传过去。

你是说 request 参数掉了么.

<rule className="org.apache.webapp.balancer.rules.RandomRedirectRule"
serverInstance="1"
maxServerInstances="3"
tcpListenAddress="127.0.0.1"
tcpListenPort="4001"
testWebPage="http://localhost:9080/clusterapp/test.jsp"
redirectUrl="http://localhost:9080/clusterapp/sessiondata.jsp" />

<rule className="org.apache.webapp.balancer.rules.RandomRedirectRule"
serverInstance="2"
maxServerInstances="3"
tcpListenAddress="127.0.0.1"
tcpListenPort="4002"
testWebPage="http://localhost:10080/clusterapp/test.jsp"
redirectUrl="http://localhost:10080/clusterapp/sessiondata.jsp" />

<rule className="org.apache.webapp.balancer.rules.RandomRedirectRule"
serverInstance="3"
maxServerInstances="3"
tcpListenAddress="127.0.0.1"
tcpListenPort="4003"
testWebPage="http://localhost:11080/clusterapp/test.jsp"
redirectUrl="http://localhost:11080/clusterapp/sessiondata.jsp" />


<!--  Default redirect if none of the above rules match  -->
<rule className="org.apache.webapp.balancer.rules.AcceptEverythingRule"
redirectUrl="http://localhost:8080/balancer/testLB.jsp" />

难道redirect之后的request url都变成了clusterapp/sessiondata.jsp

这样的话是掉了.  我也没有真正的测试过那里面的sample. 我觉得正确的应该是把整个request url转到另一台机子上.

你能否贴下Filter的源码

我反编译出来的。看doFilter那块，很清楚的用的sendRedirect。

// Decompiled by DJ v3.5.5.77 Copyright 2003 Atanas Neshkov  Date: 2006-4-5 16:14:41
// Home Page : http://members.fortunecity.com/neshkov/dj.html  - Check often for new version!
// Decompiler options: packimports(3); 
// Source File Name:   BalancerFilter.java

package org.apache.webapp.balancer;

import java.io.IOException;
import java.net.URL;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

// Referenced classes of package org.apache.webapp.balancer:
//            RulesParser, RuleChain

public class BalancerFilter
    implements Filter
{

    public BalancerFilter();
    {
    }

    protected RuleChain getRuleChain();
    {
        return ruleChain;
    }

    public void init(FilterConfig filterConfig);
        throws ServletException
    {
        context = filterConfig.getServletContext();;
        String configUrlParam = filterConfig.getInitParameter("configUrl");;
        if(configUrlParam == null);
            throw new ServletException("configUrl is required.");;
        try
        {
            java.io.InputStream input = context.getResourceAsStream(configUrlParam);;
            RulesParser parser = new RulesParser(input);;
            ruleChain = parser.getResult();;
            context.log(getClass();.getName(); + ": init();: ruleChain: " + ruleChain);;
        }
        catch(Exception e);
        {
            throw new ServletException(e);;
        }
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain);
        throws IOException, ServletException
    {
        if(response.isCommitted(););
        {
            context.log(getClass();.getName(); + ": doFilter();: not inspecting committed response.");;
            chain.doFilter(request, response);;
        } else
        if(!(request instanceof HttpServletRequest););
        {
            context.log(getClass();.getName(); + ": doFilter();: not inspecting non-Http request.");;
            chain.doFilter(request, response);;
        } else
        {
            HttpServletRequest hreq = (HttpServletRequest);request;
            HttpServletResponse hres = (HttpServletResponse);response;
            URL redirectUrl = getRuleChain();.evaluate(hreq);;
            if(redirectUrl != null);
            {
                String encoded = hres.encodeRedirectURL(redirectUrl.toString(););;
                context.log(getClass();.getName(); + ": doFilter();: redirecting request for " + hreq.getRequestURL();.toString(); + " to " + encoded);;
                hres.sendRedirect(encoded);;
            } else
            {
                chain.doFilter(request, response);;
            }
        }
    }

    public void destroy();
    {
        context = null;
        ruleChain = null;
    }

    private RuleChain ruleChain;
    private ServletContext context;
}

我用jk native connectionor实现了我需要的功能，前面加了一个apache做lb。
问题解决拉：）。就是不知道性能如何。


http://www.nihaoblog.com/1_15630.html

看了一下, 应该不会有这样的问题才对.

<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE web-app

     PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"

    "http://java.sun.com/dtd/web-app_2_3.dtd">

<web-app>

  <!-- BalancerFilter definition -->



<filter>

    <filter-name>BalancerFilter</filter-name>

    <filter-class>org.apache.webapp.balancer.BalancerFilter</filter-class>

    <init-param>

      <param-name>configUrl</param-name>

      <param-value>/WEB-INF/config/rules.xml</param-value>

    </init-param>

  </filter>



  <!-- BalancerFilter mapping -->



<filter-mapping>

    <filter-name>BalancerFilter</filter-name>

    <url-pattern>/LoadBalancer</url-pattern>

  </filter-mapping>



</web-app>

这样的话, 也就是第一次这个Filter才有用.  然后就一直request到Balancer后的那台机了.

redirect是会把request/session里保存的属性值清除的

注意, 只是第一次有效, 然后都不会经过这个Filter也就不会有Redirect. 只是进入主页的时候有效, 此时应该是没有什么属性保存的把

还是误会我的意思了。我不是访问网页。
我贴个代码吧

       HttpURLConnection uc = null;
        OutputStream conout = null;
        String strUrl = "http://127.0.0.1/aa.jsp";
        Object obj = new Object();;
        try {

            URL url = new URL(strUrl);;
            uc = (HttpURLConnection); url.openConnection();;
            uc.setRequestMethod("POST");;
            uc.setRequestProperty("Content-Type", "application/octet-stream");;
            uc.setDoOutput(true);;
            ByteArrayOutputStream bout = new ByteArrayOutputStream();;
            ObjectOutputStream out = new ObjectOutputStream(bout);;
            out.writeObject(obj);;
            byte[] mmsBytes = bout.toByteArray();;
            conout = uc.getOutputStream();;
            conout.write(mmsBytes);;
            conout.close();;
            int code = uc.getResponseCode();;
            String codeContent = java.net.URLDecoder.decode(uc.getResponseMessage();, "UTF-8");;

        } catch (Exception e); {
            e.printStackTrace();;
        } finally {
            if (uc != null); {
                uc.disconnect();;
            }
            uc = null;
        }

我每次都提交一个object到这个网页，所以每次都会经过filter的。