I'm having a problem redeploying an applications using Drools and Tomcat 6

Question

I have a spring application that uses JBoss Drools 5. It works fine except for when I attempt to redeploy (i.e. hot deploy) the application after I make a change during development. It appears that tomcat keeps a lock on 2 drools jar files, drools-compiler-5.0.1.jar and drools-core-5.0.1.jar. Since they can't be deleted the new war file does not get deployed. If my application does not make any Drools logic calls, then the hot deploy works.

Does anyone have any ideas?

Answer 1

I wouldn't know about drools specifics, but chances are, Tomcat classloader couldn't fully unload your app. Similar problem for commons-logging is explained here: http://blogs.sun.com/fkieviet/entry/classloader_leaks_the_dreaded_java

As a workaround, you can try using antiResourceLocking="true" in your $tomcat_home/conf/context.xml. This should at least help to release the locks. For more details, consult http://tomcat.apache.org/tomcat-6.0-doc/config/context.html.