I saw continuous connection Timeout from the client side during a Tomcat server load test using a http load driver written in Java. It happened on both 32/64 bit Vista only, but the same amount of client load won't cause problem in Windows 2003 or XPs. I used netstat and observed most of the connection in TIME_WAIT state, but there were no more new connection could be established.

How to reproduce:
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hostname: jtg-amd5.sfbay.sun.com (please contact the submitter for the login.)
OS: x64 Vista build 5717
JDK: Mustang build 99

1. export JAVA_HOME, the default is c:/jdk
2. Start the Tomat server by: sh c:/Tomcat/run.server &
3. Start the client stress by: sh c:/run.client &
4. Observe the test status from the console.

In the run.client script below, 100 is the number of user threads, and 200 is the number http requests send to the url. It will loop continuously in the test. You can vary these 2 parameters to adjust the load.

$JAVA_HOME/bin/java -cp sunperf/urlhammer.jar atg.core.net.URLHammer http://
$hostname:3030/index.jsp 100 200