On Fri, Nov 8, 2013 at 8:37 AM, darrell.pittman <darrell@darrellpittman.ca> wrote:
Hello,

I am new to Drools a starting a new Java EE 6 application that will use
drools.  We are not using Guvnor.  I am wondering what is the suggested way
of creating the knowledge agent and where to cache it.  EJB's shouldn't read
from the file system so I guess a Singleton EJB is out as far as loading the
knowledgebase goes.  Should I load knowledgebase in a ServletContextListener
and store it in the ServletContext and pass it into my EJB's?  What is the
recommend practice?

I faced the same problem.  There is surprisingly little information on how people do this.  The next issue you're going to face is when or if to serialize sessions (recreating them on every request is too expensive).  Then you're probably going to run into issues with how to get the KnowledgeBase if your KnowledgeAgent discovers a new one.

The "correct" way (Java EE-approved) to get the KnowledgeAgent working is to use it via a resource adapter, because KnowledgeAgent uses the filesystem and threads, both of which are no-nos in a Java EE environment.  It just so happens I wrote one a long time ago: https://github.com/ljnelson/drools-jca  I can't vouch for whether it is entirely correct (JCA is a black art) but it worked for me.

Do let us know how you end up proceeding with your architecture.

Best,
Laird

--
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