Problem with JNI and Tomcat (and threads???)

Question

Howdy,
Here is the issue - I would like some help on HOW to debug and fix this problem:
2 test use cases -
1)
a)User goes to Login.jsp, enters user and password
b) User submits to LoginServlet
c) login calls JNI code that connects to a powerbuilder(Yes I know this is ugly) PBNI code module (this is a .dll) that authenticates the user with the database
d) the servlet then redirects to another .jsp page
e) user then submits to LogoutServlet - also a JNI call to a powerbuilder PBNI code module
f) REPEAT STEPS a-e over a few times (inconsistent) and then the call to the JNI code hangs
2)
a) users does NOT goto Login.jsp, but rather calls LoginServlet and passes the userid and password as GET parms
b) user does NOT get redirected to a page (redirect code commented out)
c) user calls LogoutServlet
d) repeat steps a-c at will and no failure, no hanging
The only difference is that in case 1 (with JSP), there is a redirect and it afffected the JNI call by haniging inside JNI code.
In case 2 (without JSP) there is still a JNI call, but it does not hang. In addition, when it hangs and I stop Tomcat, the logs show cleanup entries that say:
Oct 19, 2004 9:17:09 AM org.apache.catalina.core.StandardWrapper unload
INFO: Waiting for 1 instance(s) to be deallocated
Oct 19, 2004 9:17:10 AM org.apache.catalina.core.StandardWrapper unload
INFO: Waiting for 1 instance(s) to be deallocated
Oct 19, 2004 9:17:11 AM org.apache.catalina.core.StandardWrapper unload
INFO: Waiting for 1 instance(s) to be deallocated
Is this a threading issue in Tomcat???
On would assume that the JNI code is not cleaning up after itself, but I don't believe this is the case,
and even if it was, why would I get the tomcat log cleanup entries above???
What do those cleanup entries imply about the state of Tomcat????

Answer 1

hi ,
I met the same problem this morning, and searched the www.google.com in order to solve it, as a result, your article was shown on my screen. :)
Till now I have read some technical information and solved my problems. Maybe the solution be useful to you:
==============================
error message : (Environment : Tomcat 5, Windows 2003, Mysql5)
2006-3-29 11:53:48 org.apache.catalina.core.StandardWrapper unload
message: Waiting for 2 instance(s) to be deallocated
==============================
cause: the number of connection to database exceeded.another word,too many connections.
==============================
solution: close the connection when it becomes useless for your program. :)
==============================
ps. Sorry for my weak English . hehe ....