Thank you guys for all responses. Im more than a believer in Drools,
but I actualy needed to convince other people how dont know anything
about rule engines, even when I dedicated long time to research, test
and write documents about it.

The help you provided me here is great, thanks God for open source!!


Friday, November 4, 2005, 11:43:58 AM, you wrote:

> Best way to find out if Drools is useable for you is to just ask on the
> mailing lists, we have REAL users here with REAL experience in large
> applications - Don't listen to sound bites you hear in logs from people
> who have used Drools for all of 10 minutes, with limited or no 
> experience of Rule engines.

> Mark
> Michael Neale wrote:
>> Well said Dave.
>>
>> There are all sorts of ways you can "measure" performance, but it is still
>> hard to compare. For instance, the "Miss Manners" (in drools example) is an
>> traditional test to stress rules engines. The way this is implemented in
>> drools is blindingly fast, relative to other engines (it is an optimised
>> implementation):
>> More on drools miss manners results:
>> http://jira.codehaus.org/browse/DROOLS-235
>> Miss manners:
>> http://blogs.ittoolbox.com/eai/leadership/archives/002349.asp
>>
>> Further to this, it is easy to come up with a test to show a particular
>> angle. For instance, I made a simple rule set, and tried it out with 500000
>> different facts, on my laptop drools can process upwards of 375 000 rules
>> per second when calculating the agenda (while listening to iTunes). What
>> does this number mean? I don't know, but if someone was to write about it in
>> the press I am sure things would get out of hand ! I am sure everyone would
>> rather we get on with the job, working with drools, rather then lots of
>> discussions about this and that (having said that, to answer Felipe's query,
>> we do want to make sure people feel confident). Drools marketing budget:
>> zero dollars (well, Mark will give you a cup of tea if you visit him in the
>> UK).
>>
>> There are some typical things that can cause people to get unstuck, like a
>> combination explosion if there are multiple arguments (if this is combined
>> with a large number of facts, you run up against the laws of physics), or
>> just a huge amount of recursion happening.
>>
>> There is also scaling with the number of rules (not just number of facts),
>> which is quite favourable:
>> see graph of scaling with number of rules (strangely came from an article
>> about Microsofts BRE in BizTalk):
>> http://geekswithblogs.net/images/geekswithblogs_net/cyoung/507/o_brecomp02b.
>> gif
>>
>> Finally, Mark Proctor is currently beavering away to get a tech preview out
>> of the "full" RETE engine (and more) - this will effectively replace the
>> current drools-core. Further to this, the plan is to support alternative
>> algorithms which in some cases can prove optimal. Keep in mind that the
>> drools 2.0 core was built for stability and simplicity, which is has
>> achieved. Bob Mc did an amazing job getting all that going, which is a great
>> foundation to build on.
>>
>> As for the meantime, many people are already using drools, in large and
>> small projects. RETE is only one part of the equation, many "new" rule
>> engines claim to not even want to support RETE - it is to complex an issue
>> to come down to a number or a single fact to latch on to.
>> Simon Harris on drools: (he has contributed a lot since this post):
>> http://www.redhillconsulting.com.au/blogs/simon/archives/000208.html
>>
>> Share your stories !
>>
>> if you want to help out and are handy with a profiler, find some hot spots:
>> http://drools.org/Hot+Spots
>>
>> At the end of the day drools is completely open, so get involved, have a
>> poke around and see what you can do !
>>
>>
>> Michael. 
>> (about to take off for 2 weeks of sitting around on a beach, and by the
>> pool).
>>
>> -----Original Message-----
>> From: Hamu, Dave [mailto:[EMAIL PROTECTED] 
>> Sent: Friday, 4 November 2005 9:41 AM
>> To: [email protected]; Felipe Piccolini
>> Subject: RE: [drools-user] Comment on drools performance.
>>
>> All-
>>
>> Yeah, there are a bunch of misinformed people who have made disparaging
>> remarks about Drools on various blogs.  Either they really haven't attempted
>> to work with drools, or they simply read something negative that someone
>> else wrote and accepted it as fact.  In many cases, they are writing because
>> they have an agenda to promote some other commercial or open-source product.
>>
>>
>> It is conspicuous that these bloggers rarely have anything by way of
>> contrast or comparison to say that demonstrates that their favorite solution
>> is fundamentally superior.  In the rare case, that there are comments that
>> assert that a particular product may be superior to DROOLS, it is rare that
>> they have done a good job of researching the differences.  
>>
>> Perhaps the one area that Drools does not compare favorably against
>> commercial products is the lack of a GUI front end and in the lack of an
>> integrated tool to easily manage rules repositories (although that will
>> probably be forthcoming now that DROOLS is part of JBOSS).  That said, I
>> would urge people to look at the commercial products and realize that there
>> are certain hoops that you need to jump through to utilize the rule
>> repositories and operate within the UI -- trust someone who has worked with
>> a variety of these products, it's no picnic working with the commercial
>> products, and you typically have a 1/4 M$ entry fee (generally much higher
>> than that) for even a pilot project.
>>
>> That's not to say that certain rules engines might not be a better fit for
>> some projects than others, but I think that the analysis that is needed to
>> compare the advantages and disadvantages of one engine over another is much,
>> much more than what these bloggers have shown.
>>
>> - Dave
>>
>>
>>
>> -----Original Message-----
>> From: Felipe Piccolini [mailto:[EMAIL PROTECTED]
>> Sent: Thursday, November 03, 2005 2:30 PM
>> To: [email protected]
>> Subject: [drools-user] Comment on drools performance.
>>
>> Guys,
>>
>>  In this link a guy comment on Drools's performance and some people in my
>> company are worried about the impact this can produce on the application
>> (beacuse of course I introduced Drools on it). I know  this is not a real
>> problem, and we are using rule engine in a smart  way so working memory and
>> rules are no over loaded, but the top  managers need more facts than just my
>> opinion, and Im asking all of  you guys about experiences and real comments
>> about this link and  about your application performance and scalability
>> using Drools.
>>
>>  
>> http://bizrules.eclipsedevelopersjournal.com/some_thoughts_about_drools.
>> htm
>>  
>>  Thaks a lot.
>>
>>   
>>
>> ----------------------
>> Felipe Piccolini
>> [EMAIL PROTECTED]
>>
>>
>>
>>   


--------------------------
Felipe Piccolini
[EMAIL PROTECTED]

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