RE: [cinjug-users] JDBC driver problems on session expiration

["Jason Kretzer/STAR BASE Consulting Inc." <JKretzer@xxxxxxxxxxxxxxx>]

I don't maintain a connection to the
database.  This happens when trying to get a connection.

-Jason

"Robert Casto" <robert@xxxxxxxxxxxxx>

08/04/2004 02:21 PM

To	"'Jason Kretzer/STAR BASE Consulting Inc.'" <JKretzer@xxxxxxxxxxxxxxx>, <users@xxxxxxxxxx>
cc
Subject	RE: [cinjug-users] JDBC driver problems on session expiration

Jason,
 
I have had trouble with database
drives as well.
 
What I did was to institute
a timeout. If the connection to the database is older than say 5 minutes,
I throw it away and try to log into the database again.
 
My guess is that the connection
has closed and the driver is not handling things properly. I found this
to be true when working with SQL Server and my guess is that your having
the same problem. I do the throw away and establish a new connection without
the user knowing what happened. My logs show the event, but that is the
only indication that something was done.
 
Best of luck!
Robert Casto
President - CinciJava LLC
Phone: 513-755-2221
FAX: 831-307-7638
robert@xxxxxxxxxxxxx

---

From: Jason Kretzer/STAR BASE Consulting
Inc. [mailto:JKretzer@xxxxxxxxxxxxxxx] 
Sent: Wednesday, August 04, 2004 2:08 PM
To: users@xxxxxxxxxx
Subject: [cinjug-users] JDBC driver problems on session expiration
 

Hello all, 

I am having an intermittent problem with session expiration handling.  

First, my background specs.  
WSAD 5.1.1 
Windows XP Pro 
using WSAD testing server 
using a DB2 backend 
using jcc DB2 driver 

Here is my scenario which happens maybe 5% of the time:  
I log in to my webapp.  I let the session expire.  When I click
on a link, it goes to my error screen and tells me the session is expired.
 So, I go back to the login(html) page which posts to the LoginVerification
servlet.  When it gets to line 305(lines 304 and 305 are below for
reference), I get the following(labelled First Error below) in my console
window.  Upon seeing this, I type the url for my login page again
and try to log in again.  This action produces another error in my
console window, labelled Second Error below.  I then must restart
the test server because the JVM core dumps.


Any ideas?  I would hate to have this happen when the application
goes live. 

Thanks, 

-Jason 



LINE 304:   Class.forName("com.ibm.db2.jcc.DB2Driver");
LINE 305:   conn = DriverManager.getConnection("jdbc:db2://ssbc10:50000/ASSESS",
usernameStr ,passwordStr );



===========================================
First Error 



[8/4/04 12:53:05:790 GMT-05:00] 55e731f5 WebGroup      E
SRVE0026E: [Servlet Error]-[Class com/ibm/db2/jcc/SQLJLogWriter violates
loader constraints:  definition mismatch between parent and child
loaders]: java.lang.LinkageError: Class com/ibm/db2/jcc/SQLJLogWriter violates
loader constraints:  definition mismatch between parent and child
loaders 
        at com.ibm.db2.jcc.DB2Driver.connect(DB2Driver.java:244)
        at java.sql.DriverManager.getConnection(DriverManager.java:538)
        at java.sql.DriverManager.getConnection(DriverManager.java:188)
        at com.starbaseinc.www.online.teckchek.administration.common.LoginVerification.doPost(LoginVerification.java:305)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at com.ibm.ws.webcontainer.servlet.StrictServletInstance.doService(StrictServletInstance.java:110)
        at com.ibm.ws.webcontainer.servlet.StrictLifecycleServlet._service(StrictLifecycleServlet.java:174)
        at com.ibm.ws.webcontainer.servlet.IdleServletState.service(StrictLifecycleServlet.java:313)
        at com.ibm.ws.webcontainer.servlet.StrictLifecycleServlet.service(StrictLifecycleServlet.java:116)
        at com.ibm.ws.webcontainer.servlet.ServletInstance.service(ServletInstance.java:283)
        at com.ibm.ws.webcontainer.servlet.ValidServletReferenceState.dispatch(ValidServletReferenceState.java:42)
        at com.ibm.ws.webcontainer.servlet.ServletInstanceReference.dispatch(ServletInstanceReference.java:40)
        at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.handleWebAppDispatch(WebAppRequestDispatcher.java:974)
        at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.dispatch(WebAppRequestDispatcher.java:555)
        at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.forward(WebAppRequestDispatcher.java:200)
        at com.ibm.ws.webcontainer.srt.WebAppInvoker.doForward(WebAppInvoker.java:119)
        at com.ibm.ws.webcontainer.srt.WebAppInvoker.handleInvocationHook(WebAppInvoker.java:276)
        at com.ibm.ws.webcontainer.cache.invocation.CachedInvocation.handleInvocation(CachedInvocation.java:71)
        at com.ibm.ws.webcontainer.cache.invocation.CacheableInvocationContext.invoke(CacheableInvocationContext.java:114)
        at com.ibm.ws.webcontainer.srp.ServletRequestProcessor.dispatchByURI(ServletRequestProcessor.java:186)
        at com.ibm.ws.webcontainer.oselistener.OSEListenerDispatcher.service(OSEListener.java:334)
        at com.ibm.ws.webcontainer.http.HttpConnection.handleRequest(HttpConnection.java:56)
        at com.ibm.ws.http.HttpConnection.readAndHandleRequest(HttpConnection.java:618)
        at com.ibm.ws.http.HttpConnection.run(HttpConnection.java:439)
        at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:593)


======================================================
Second Error 

JVMDG217: Dump Handler is Processing a Signal - Please Wait.
JVMDG303: JVM Requesting Java core file
JVMDG304: Java core file written to C:\Program Files\IBM\WebSphere Studio\Application
Developer\v5.1.1\javacore.20040804.135626.3884.txt
JVMDG215: Dump Handler has Processed Exception Signal 11.