Dear mailing-list/forum reader,

this post is quite long, so thanks in advance for willing to read through this ;-)

I need to set up a test for using Guvnor in cluster.

I searched in the archive, and I know there are few threads regarding this.

But some are for me already too "high-level", bcs I didn't have many experiences on this, so I'd like to start from the beginning

Would be very thankful If you could share some advices on development strategies, based on following situation and questions:

Situation:

- several instances of one web-app (on several servers), say MyApp , with one MySQL server as back-end, should perform some value persisting into DB; each operation should get feedbacks, if this violates any rules defined using the BRMS.

- Rules will be updated rarely (approx. once a year)

1. As my understanding, Guvnor is just another web-app with DB on the back-end. 

If MyApp has its DB already prefilled (because this is already running for quite some time) and according to the documentation, BRMS will create the tables the first time it is started if it's running again empty RDBMS, is it still possible to use this DB anyway? Is there any additional maintenance/handling required to do this?

2.  Which one is in general the better (or correct) strategy:

- use one common DB for both MyApp and Guvnor or separate DBs (use another external RDBMS for Guvnor)?

- having as many instances of Guvnor as MyApp, or just having one single instance of this?

3. Having seen the documentation on integrating rules from Guvnor with app, I understand that there's need of using RuleAgent.

- RuleAgent (and Statefull/StatelessSession too) is still part of the "old" drools-core. Would it be later a problem to switch to the new APIs?

- I need to get the RuleClient from a stateless EJB; does this mean only StatelessSession is usable in this case?

4. How can I correctly implement the communication between MyApp and Guvnor?

I wouldn't like to fetching the rule base each time the persisting operation is performed.

- Which alternatives are there to avoid constantly communicate with Guvnor (especially if there is actually no rule-update happened), but still getting the most actual rule?

- Maybe kind of storing the rules in DB which is keep synchronized with Guvnor, and MyApp just fetch the rules from DB?

Again, any reply would be very appreciated.

Regards

Paul