[rules-users] Looking for a place to start with drools

Fri Sep 17 02:56:16 EDT 2010

Hi Dean,

Re #2; take a look at KnowledgeBuilder (which I assume you may have already)
which loads Decision Table files (XLS) and creates a KnowledgeBase wherefrom
you create your KnowledgeSessions. If you really want DRL from your XLS's
look at ExternalSpreadsheetCompiler in the drools-decisiontables project
(the test shows how it can be used).

IMO, I'd read around MarshallerFactory and Marshaller regarding
serialisation of your KnowledgeSession. Ideally you might like to cache the
KnowledgeBase itself, but I couldn't find much about serialising it... :-(

The Mortgage example in the examples-brms folder shows how you could load
rules from Guvnor - although it looks a little out of date referencing
RuleBase and the like rather than KnowledgeBase, but the principle is the
same.

Hope this helps a little.

Mike

2010/9/16 Dean Whisnant <dean at basys.com>

>  Mike,
>
>
>
> I am working on this project in phases.  The initial phase is to label all
> of my current logic as either core code, trading partner specific code, or
> customer specific code.  Once these three levels are determined, we will be
> recreating standard versions of the first two in a rules engine, perhaps all
> in one package.  Then at each customer we will implements a package that has
> their specific requirements.
>
>
>
> Looking at your responses below I have more explaining to do.
>
>
>
> 1)      We are considering pulling the standard code and trading partner
> rules out into a cloud, off the customer’s site, so that we do not have
> deployment issues that we have today. But we would allow the specific
> customer rules to execute on their local server. So at a minimum I would
> need to do two packages (one for the rules in the cloud and the second for
> the rules on their server).  Perhaps I still need to understand the
> relationship of a .drl file to a package, though in my mind this is a 1 to 1
> relationship.
>
>
>
> 2)      I hear you on the responsibility part for giving our users the
> ability to author their own rules in Guvnor.  Thinking back to the last
> three points in my original mail I’m really looking to balance which way
> would be best to expose this to our customers (guvnor vs. DTs).  Perhaps
> there is more I need to understand about the limitations of each.  If I
> understood your response to #4 below it is that I would want to create one
> decision table for a logical rule (whether that rule is one simple if then
> else or it is a longer case statements).  That being said, would I then have
> 40 spreadsheets for them to manage and change for the different logical
> rules?  How would that be from a performance standpoint?  Is there a process
> to take these 40 spreadsheets and convert them into one .drl file? Or are
> they each then a .drl file?  From a performance standpoint, are these loaded
> from spreadsheet each time a user runs an EDI load?  Or are they made binary
> once (or whenever there are changes) and thus not having to “recompile” each
> time?
>
> You might read from this that the idea of packaging for production is
> something I’m still struggling to understand.  If anyone has a good source
> to show an example of actual distribution that would be cool.  I’ve been
> reading through the manuals and everything seems to stop with the examples
> as being .java and .drl files.
>
>
>
> Thank you for your assistance.
>
>
>
> --Dean
>
>
>
> *From:* rules-users-bounces at lists.jboss.org [mailto:
> rules-users-bounces at lists.jboss.org] *On Behalf Of *Michael Anstis
> *Sent:* Thursday, September 16, 2010 11:40 AM
> *To:* Rules Users List
> *Subject:* Re: [rules-users] Looking for a place to start with drools
>
>
>
> Of course you could leverage the benefits of using Drools to directly
> replace your hard-coded logic first and leave the enhancements around
> permitting your users to define their own rules to a later date rather than
> push into one release; if time is a concern. Would the Drools road be any
> more different than allowing your users to define their own hard-coded rules
> now using a proprietary mechanism?
>
> >> 1.       How would you package these types of rules?  I have three
> categories as stated above and it seems logical that I would package them in
> that manner.  However within each group there are logical groupings of
> rules.  In the customer rules I may have a couple dozen on how to populate a
> field that deals with adding comments and another couple dozen having to
> deal with setting certain fields with specific codes that are based upon
> incoming data.  Two quite different logical areas within our software.
>
> Horses for courses. Nothing stopping you deploying multiple packages if
> need be, but it'll be harder to try and make course grained packages more
> fine grained if you later wish you'd done this from the start.
>
> >> 2.       How would you deal with the GUI? Is Guvnor truly something I
> can setup in a way that my end users can manipulate without “damaging” the
> custom ruleset?
>
> With power comes responsibility. If users are given the power to define
> their own custom rules they have to take responsibility for damaging them
> too. There is the ability to run tests against rules in Guvnor, but that
> won't stop somebody from mucking them up. I'd recommend providing for UAT. I
> don't what exposure your clients have to "testing" new features now..
>
> >> 3.       Within Guvnor, how would you handle the possibility of there
> being over 2,000 fields to choose from to form a rule?
>
> I believe there is functionality in 5.1 for Working Sets that allow subsets
> of fields\fact types to be exposed.
>
> >> 4.       What is the performance hit if we were to make each customer
> rule part of once decision table or another? Would you even consider this as
> an option?
>
> One decision table for all users at all customers? One DT per rule is
> normally the intent, or did I misunderstand.
>
> Good luck.
>
>
>
> Mike
>
>
>
> On 16 September 2010 15:00, Gustavo Tenrreiro <gustavo at tenrreiro.com>
> wrote:
>
> Hi Dean,
>
> I ve only been working with Drools for about a couple of months.
> My first impression was that it was a great tool and very
> straightforward. But as I got deeper into it, I found a lot of
> gotchas, and things I didn't quite understand how they worked ( for
> many I still don't ). Finding definitive answers to those questions
> has been hard. Even though this forum, as well as the IRC chat are
> very helpful, the flow of information is somewhat limited.
> If what you are doing has some complexity beyond the simple examples
> provided by the documentation, and sample code, then you will probably
> get stuck at some point, and burn a lot of time trying to figure out
> the problem.
>
> So if you are on a tight budget that requires tight deadlines using
> Drools to replace your existing code would be a high risk proposition
> I believe.
>
> On the other hand, the Drools's potential to simplify, and streamline
> my system is great. if I manage to get it to do what I want it to do
> it would be a huge win for my organization, and the Drools system
> would be mostly responsible for that.
>
> So to summarise, jumping into the Drools bandwagon would be an
> "educated bet", but a bet nonetheless.
>
> Hope that helps.
>
> Thanks
>
>
> 2010/9/16 Dean Whisnant <dean at basys.com>:
>
> > I am investigating using Drools for our company’s EDI processing.  The
> > nature of our software system is that each of our clients (dozens) has a
> > full distribution of our base software and in the past we would make
> custom
> > changes to that base software at each of their sites based upon their
> > trading partners and business needs. For the most part these changes
> > involved nothing more than if-then statements for rather simple logic,
> but
> > that would become complicated at certain customers where there were large
> > numbers of trading partners and specific customer needs.  In general we
> saw
> > 2,000 lines of code swell to 4-6,000 lines of code.
> >
> >
> >
> > We are in the process of rewriting this portion of our code and are
> > entertaining using drools to allow us to 1) create a standard ruleset, 2)
> > create a ruleset specific to a trading partner (many customers share some
> > common trading partners), and 3) create a customer business ruleset that
> > they can maintain through some GUI tool (Guvnor).
> >
> >
> >
> > So far, I’ve created a sample java program that has classes representing
> > some of our data files (UniData environment using uniobjects) and have
> been
> > working with a single .drl file to test out general rules.  I appear to
> be
> > able to write just about any rule I’ve needed in the past with no issues,
> > including rules that spawn processes within my native software.
> >
> >
> >
> > These are my questions:
> >
> >
> >
> > 1.       How would you package these types of rules?  I have three
> > categories as stated above and it seems logical that I would package them
> in
> > that manner.  However within each group there are logical groupings of
> > rules.  In the customer rules I may have a couple dozen on how to
> populate a
> > field that deals with adding comments and another couple dozen having to
> > deal with setting certain fields with specific codes that are based upon
> > incoming data.  Two quite different logical areas within our software.
> >
> > 2.       How would you deal with the GUI? Is Guvnor truly something I can
> > setup in a way that my end users can manipulate without “damaging” the
> > custom ruelset?
> >
> > 3.       Within Guvnor, how would you handle the possibility of there
> being
> > over 2,000 fields to choose from to form a rule?
> >
> > 4.       What is the performance hit if we were to make each customer
> rule
> > part of once decision table or another? Would you even consider this as
> an
> > option?
> >
> >
> >
> > Thank you!
> >
> >
> >
> > --Dean
> >
>
> > _______________________________________________
> > rules-users mailing list
> > rules-users at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/rules-users
> >
> >
>
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