Error opening socket when running multi-threaded SOAP client

[di...@codejawa.com]

Hello All,

I've been able to run SOAP samples (addressbook etc), the server &
client side run fine.

Now I'd like to load-test the SOAP server of accepting multiple SOAP
request, for this test, I modify the apache soap's sample of
addressbook, i.e. AddressBook.java. I make this class implements
Runnable, then make some thread inside of it.

then as usual I run it by using:
java samples.addressbook.GetAddressThread
http://localhost:8080/soap/servlet/rpcrouter "John B. Good"

my result:
for 1-20 thread, the results are okay. no error is generated.
for > 21 thread, I got this multiple error messages:

<preceded with some other 123 Main Street....>

123 Main Street
Anytown, NY 12345
(123) 456-7890

Caught SOAPException (SOAP-ENV:Client): Error opening socket: Connection refused
: connect
Caught SOAPException (SOAP-ENV:Client): Error opening socket: Connection refused
: connect
Caught SOAPException (SOAP-ENV:Client): Error opening socket: Connection refused
: connect
Caught SOAPException (SOAP-ENV:Client): Error opening socket: Connection refused
: connect

123 Main Street
Anytown, NY 12345

<continued with another 123....>

At first, I suspected the "error opening socket" message is related
with the Tomcat (I use Tomcat 3.2.1), but i guess it's not,  because
when I call a servlet (that the doProcess() takes processing about 6-7
seconds) from similar multi-threaded java classes, even for 50+
threaded, no error messages are generated.

What might be the problem? Please help me point out the solution.
I'm using Tomcat 3.2.1, Apache Soap 2.2, jdk 1.3.1, Windows 2000, and
SoapServer & SoapClient resides locally.

Thank you very much in advance.

-- 
Best regards,
 dion                            
mailto:dion@codejawa.com