Drools vs. Cognos

Question

I am relatively new to the concept of rules engines and was trying to work with Drools.

Has anyone already worked this tool before and is it similar to Cognos?

My understanding was that Cognos is a reporting tool and Drools will promote more increased control over the business logic implemented.

Am I on the right track? Any link which would help me differentiate between the 2 would also be helpful.

Thank you.

Answer 1

Cognos is a business intelligence reporting tool. It is meant to query over data sources including data warehouses and data marts, to help provide insight into your data and help you make decisions, view trends, etc. Here is IBM's Cognos product page. Here is a definition of Cognos from Wikipedia which I find helpful.

Drools is a Rete algorithm based Java rules engine that allows you to define business rules within your application and then have your application validate against those rules. Here is its definition from Wikipedia. And here is the Drools community page.

We actually use Drools in some of our applications for client side verification of business rules. And our business is planning on using Cognos (and another tool called QlikView) to do business intelligence reporting over our data warehouses and data marts.

As for how you use Drools, I'd look at the community page. In the version we used (2.0-Beta-10, which was way before Drools was acquired by JBoss) you generally define your rules in XML based files with a .drl extension from what I remember. We use an older version of Drools so it may have changed since then. We also extended Drools in our case so we could write our rules in Java code for run time debugging versus using XML files (since our Business analysts weren't writing the rules anyway).

Hope this helps!

Answer 2

You can use Drools & jBPM5 if your application will define Business Processes and Business Rules. The business rules will allow you to define business logic in a declarative way and the rule engine will allow you to do inferences over the information that you have in your domain. Visiting the community sites and looking for examples will probably help you out to understand how the project look like now and how you can use it. Cheers