Hi, We are using Drools VERY succesfuly around 3 years (We started with version 2.x). And it has being so usefull that now we have a very big system running on more than one customer in telecom market.
Main (Obvious) Advantages: 1-All open source and community envolvment benefits (Well tested code, new and innovative use cases, new features added quickly, source code available........and ....many more) 2-Very simple, quick, cheap and clean implementation of new features. 3-No need to re-build entire system due to new or changes in business rules/needs, VERY high degree of flexibility and freedom 4-Knowledge is "almost explicit" and start to become formal for the organization 5-You can build framworks that accepts different Object Models and Rules, while all the infra-structure supporting it is the same, so with basically same code we can build different solutions. This leads to rocket-time implementations and extremally short learning curves. What we use Drools for? 1-As a rules engine as usual 2-For reporting stuff (Good for generating reports with different views of data, very easy to reformat dates, numbers and so on...) 3-For discimination networks (We are affraid of shadow facts on this :) ) Currently we do have a server running around 300 rules, where we assert millions of facts at once. The objective is to guide and rate telecom usage events. We are able to apply those 300 rules over 20 Milion facts and get results (Guided and Rated) around 1 hour(Note: First we have to read many binary files, perform a charset conversion on data, load it in our object model, assert objects in working memory, apply around 200 rules to enrich the data, assert again in a new working memory, and rate the events accessing external RDBMS databases - caching results of course). Acctually what we do is to in batch/server workflow assert those facts twice (Two working memories) in sequence. The first one is to "enrich" the data (Discrimination Network...) and instead of modifying the events here, we just go to next step and then assert those facts again and apply rating rules. It seams to perform better. Issues and Cares: 1-Avoid at ANY cost cartesian products. It kills you. This is a common mistake, easy to do, easy to detect (Symptons are typical...Slow down performance, memory consuption is very high, application will probably swap), hard to find where it is and easy to solve. 2-Memory consumption is always an issue 3-Have a very good design to access external databases (If possible, think about on having a database cache running outside your JVM) 4-Follows Edson Tirelli's tips and tricks. 5-Be carefull with numbers and dates formatting, conversion and calculation (as in my experience Java performs poorly on this area) -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Anstis, Michael (M.) Sent: quarta-feira, 18 de julho de 2007 11:10 To: Rules Users List Subject: RE: [rules-users] Entreprise using Drools with success We short-listed Drools against ILOG and Fair Issac. V4.0 was to be the technical winner but for (a) per CPU support cost and (b) internal politics. It was (and still is) a shame we had to "sell out" :-( Mike -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brian Sam-Bodden Sent: 18 July 2007 15:01 To: Rules Users List Subject: Re: [rules-users] Entreprise using Drools with success We deployed a Drools based solution to a client in the pharmaceutical distribution world (Fortune 100 company :-). We used Drools to power the decisions an interactive voice ordering system. A small number of rules initially but growing constantly based on user metrics. System has been running for a couple of years now. On 7/18/07, Geoffrey Wiseman <[EMAIL PROTECTED]> wrote: > On 7/18/07, hypnosat7 <[EMAIL PROTECTED]> wrote: > > Is there any companies which used Drools successfully ? > > Tell us more about your experiences, I need it to make decision > > > > I've worked at a company that used it internally in its product before, > although I don't work there now. It worked well for us; and everything I've > seen about subsequent releases implies it's better than ever. > > Now, that's not to say that any of us can predict your success; it does > depend on how you plan on using it, but for the most part, I'd say Drools / > JBoss Rules is a relatively easy-to-use, powerful and performant choice for > many of the things people consider using it for. > > - Geoffrey > -- > Geoffrey Wiseman > > _______________________________________________ > rules-users mailing list > rules-users@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > _______________________________________________ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
