Undeployment of JDBC Driver

[darranl]

Hi,

I have been having a few problems with class loaders recently so I have been using a profilling tool to find out what object instances are in memory at various times.

My application is packaged into a single ear file that amongst other things contains the JDBC drivers for MySQL and a mysql-ds.xml.

After deploying the ear and running the application I can see that there are a number of instances of the MySQL classes in memory.

After undeployment a lot of these instances disappear but a few remain.

After undeployment does JBoss attempt to deregister the driver? Or are JDBC drivers left registered till the next time JBoss is restarted?

The bahaviour is the same if I put the driver jar in lib and the mysql-ds.xml in deploy.

[darranl]

Sorry forgot to say this is on JBoss 3.2.1

[adrian.brock]

I have fixed the unregistration of the driver
at undeploy, however I can't get redeploy of
Driver classes to work.

There is some horrible class caching somewhere
in java.sql.Driver, it looks like a horrible attempt
at security for applets judging by the hint
in the javadocs.

Regards,
Adrian

[darranl]

Do you know if the Driver instance was garbage collected between your deployments?

Is it possible that the static initialisation is not being called the second time the class is loaded?

[adrian.brock]

The Driver instance is garbage collected.
The driver is re-registered with the DriverManager,
but it doesn't use it.

It says "skipping" if I set the logWriter to System.out,
it seems to be caching the original class or classloader
somewhere then saying I cannot use the driver
because I would load a different class for the driver.

Regards,
Adrian

[darranl]

Adrian,

Just wanted to check to see if you have made any further progress on this issue?

Should this be logged as a bug at sourceforge so it can be tracked?