Shadow facts(was JRules\Drools benchmarking)
by Hehl, Thomas
I did some reading about shadow facts and I was thinking about turning them
off, but it seems to be that if I use stateless sessions (session.execute())
that shadow facts are irrelevant. Is this true?
_____
From: rules-users-bounces(a)lists.jboss.org
[mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Edson Tirelli
Sent: Thursday, May 15, 2008 10:00 AM
To: Rules Users List
Subject: Re: [rules-users] JRules\Drools benchmarking...
It seems you are using a good strategy to do your tests. But still, it is
difficult to explain why one is slower than the other without seeing the
actual test code. This is because all the engines have stronger and weaker
spots. Just to mention one example, some engines (not talking specifically
about drools and jrules, but about all engines) implement faster alpha
evaluation, others implement faster beta (join) evaluation, others implement
good optimizations for not() while others may focus on eval(), etc. It is up
to the point that when comparing 2 engines, one performs better in hardware
with a bigger L2 cache while the other performs better in hardware with a
smaller L2 cache.
So, best I can do without looking at the actual tests is provide you some
tips:
1. First of all, are you using Drools 4.0.7? It is very important that you
use this version over the previous ones.
2. Are you using stateful or stateless sessions? If you are using stateful
sessions are you calling dispose() after using the session? If not, you are
inflating your memory and certainly causing the engine to run slower over
time.
3. Are you sharing the rulebase among multiple requests? The drools rulebase
is designed to be shared and the compilation process is eager and pretty
heavy compared to session creation. So, it pays off to create the rulebase
once and share among requests.
4. Did you disabled shadow facts? Test cases usually use a really small fact
base, so would not be much affected by shadow facts, but still, disabling
them improves performance, but require some best practices to be followed.
5. Do your rules follow best practices (similar to SQL writing best
practices), i.e., write the most constraining patterns first, write the most
constraining restrictions first, etc? Do you write patterns in the same
order among rules to maximize node sharing? I guess you do, but worth
mentioning anyway.
Anyway, just some tips.
Regarding the jrules blog, I know it, but I make a bet with you. Download
the manners benchmark to your machine, make sure the rules are the correct
ones (not cheated ones), run the test on both engines and share the results.
I pay you a beer if you get results similar to those published in the blog.
:)
My point is not that we are faster (what I know we are) or them are
faster. My point is that perf benchmarks for rules engines are a really
tricky matter, with lots of variables involved, that make every test case
configuration unique. Try to reproduce in a different environment and you
will get different performance rates between the engines.
That is why, our recommendation is to always do what you are doing: try
your own use case. Now, whatever you are trying, I'm sure it is possible to
optimize if we see the test case, but is it worth it? Or the perf as it is
already meets your requirements?
Cheers,
Edson
PS: I'm serious about the beer... ;) run and share the results with us...
2008/5/15 mmquelo massi <mmquelo(a)gmail.com <mailto:mmquelo@gmail.com> >:
You r right...
I have to tell you what I have done...
I did not define a "stand-alone" benchmark like the "Manners" one.
I benchmarked a real j2ee application.
I have got jrules deployed with a resource adapter and drools deployed
with simple jars libraries plus jbrms.
Jrules uses a "bres" module which does the same trick jbrms does.
Both of them are deployed on the same AS, in the same time, same
machine (my laptop: dual core 2 duo 1.66, 2GB).
Using the inversion of control pattern I found out how to "switch the
rule engine" at run-time. So I can easily choose then rule engine to
use between drools and jrules.
Ofcourse thay have got two separate rule repositories but both of them
persist the rules on the same DB which is Derby.
The j2ee application I benchmarked sends a request object to the
current rule engine and get back a reply from it. I just measured the
elapsed time between the request and reply generation using drools
first and the jrules.
I did the measurements tens of times.
Both rule engines implement the same rules and the Drools rules (which
I personally implemented) are at least as optimized as the jrules
ones. In the Jrules version of the rules there are a lot of
"Eval(...)" blocks in the Drools version I did not use the "Eval()" at
all ....but I just did pattern matching.
If you want i can send you a more specific documentation but I hope
this explanation will be enough to show you that the measurements I
have done are not that bad.
In any case I noticed that after a warming-up phase, the drools engine
gives a reply back 3 times slower than the jrules engine.
The link I have sent show you something related to it, It reports the
manners execution time using drools and jrules. As you can see the
difference is a 1,5x factor....so I was wrong... drools is not that
slow. In anycase seems to be slower that jrules.
Look at this:
http://blogs.ilog.com/brms/wp-content/uploads/2007/10/jrules-perf-manners.pn
g
<http://blogs.ilog.com/brms/wp-content/uploads/2007/10/jrules-perf-manners.p
ng>
Massimiliano
On 5/15/08, Edson Tirelli <tirelli(a)post.com <mailto:tirelli@post.com> >
wrote:
> The old recurring performance evaluation question... :)
>
> You know that an explanation can only be made after having looked at
the
> tests used in the benchmark, the actual rules used by both products,
> hardware specs, etc... so, not quite sure what answer do you want?
>
> For instance, there are a lot of people that think exactly the
contrary.
> Just one example:
>
http://blog.athico.com/2007/08/drools-vs-jrules-performance-and-future.html
<http://blog.athico.com/2007/08/drools-vs-jrules-performance-and-future.html
>
>
> My preferred answer is still:
>
> "In 99% of the applications, the bottleneck is IO: databases, network,
etc.
> So, test your use case with both products, make sure it performs well
> enough, add to your analysis the products feature set, expressiveness
power,
> product flexibility, cost, professionals availability, support quality,
etc,
> and choose the one that best fits you."
>
> That is because I'm sure, whatever your rules are, in whatever product
> you try them, they can be further optimized by having a product expert
> looking into them. But what is the point?
>
> Cheers,
> Edson
>
>
>
> 2008/5/14 mmquelo massi <mmquelo(a)gmail.com <mailto:mmquelo@gmail.com> >:
>
>>
>> Hi everybody,
>>
>> I did a benchmark on Drools\Jrules.
>>
>> I found out that drools is about 2,5-3 times slower than Jrules.
>>
>> How comes?
>>
>> The results I got are quite similar to the ones in:
>>
>>
>>
http://images.google.com/imgres?imgurl=http://blogs.ilog.com/brms/wp-content
/uploads/2007/10/jrules-perf-manners.png&imgrefurl=http://blogs.ilog.com/brm
s/category/jrules/&h=516&w=722&sz=19&hl=it&start=1&um=1&tbnid=YBqwC0nwaSLxwM
:&tbnh=100&tbnw=140&prev=/images%3Fq%3Dbrms%2Bbencmark%26um%3D1%26hl%3Dit
>>
>> Any explanations?
>>
>> Thank you.
>>
>> Bye
>>
>> Massi
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users(a)lists.jboss.org <mailto:rules-users@lists.jboss.org>
>> https://lists.jboss.org/mailman/listinfo/rules-users
<https://lists.jboss.org/mailman/listinfo/rules-users>
>>
>>
>
>
> --
> Edson Tirelli
> JBoss Drools Core Development
> Office: +55 11 3529-6000
> Mobile: +55 11 9287-5646
> JBoss, a division of Red Hat @ www.jboss.com <http://www.jboss.com>
>
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--
Edson Tirelli
JBoss Drools Core Development
Office: +55 11 3529-6000
Mobile: +55 11 9287-5646
JBoss, a division of Red Hat @ www.jboss.com <http://www.jboss.com>
17 years, 7 months
Multithreading Rulebase Parsing Threadsafe
by Barry K
We have an application with 2 rules engines and we load the rules on startup.
Is creation of a rulebase threadsafe?
Can I load both rulebases using the code below concurrently in 4.07 ?
I encountered issues multithreading this in 4.01 but in prototyping for our
4.07 upgrade I have not encountered the same issues.
PackageBuilder builder = new PackageBuilder(pkgBuilderCfg);
builder.addPackageFromDrl( new StringReader(ruleset) );
RuleBase ruleBase = RuleBaseFactory.newRuleBase();
Thanks
Barry
--
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17 years, 7 months
Re: Java vs mvel dialects
by Krishna Satya
>
> Edson, Thanks so much for the reply. It makes perfect sense to me. I
> really appreciate it.
- Krishna
> Krishna,
>
> The dialect configuration affects only semantic code blocks. I.e.,
> consequences, eval() blocks, etc.
> They are designed to be interchangeable. That is why the examples have
> rules using each of the dialects.
>
> It is mostly a matter of taste, but MVEL is a script language and as so
> has syntax sugar for nested object access, collections, maps, arrays etc...
> nothing more than that. Also, MVEL supports java syntax anyway. For
> instance, assuming you have a class:
>
> Person {
> Map<String, Address> addresses;
> // gets/sets
> }
>
> The following consequence should run just fine, both in java and MVEL:
>
> then
> $person.getAddresses().get("home").setStreetName("my street");
> end
>
> Although, MVEL allows you to use a cleaner syntax:
>
> then
> $person.addresses["home"].streetName = "my street";
> end
>
> It is mostly a matter of taste.
>
> []s
> Edson
>
> 2008/5/14 Krishna Satya <krishna.ksatya(a)gmail.com>:
>
> > Hi, I am trying to understand the difference in how drl rules are
> expressed
> > via the java or mvel dialects. Looking at the drools-examples it is not
> > exactly clear. I was looking at the PetStore.drl which seems to specify
> the
> > dialects for various rules using both java and mvel. Are there any
> > references to examples which showcase a rule that is expressed both
> through
> > java and mvel dialects so it is clear what the differences are. The
> rules
> > in the PetStore.drl which specify java or mvel syntactically seem to look
> > the same.
> >
> > Also, are there any general suggestions as to when a rule author should
> use
> > the java or the mvel dialect.
> >
> > Thanks.
> > - K
> >
> >
> > _______________________________________________
> > rules-users mailing list
> > rules-users(a)lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/rules-users
> >
> >
>
>
> --
> Edson Tirelli
> JBoss Drools Core Development
> Office: +55 11 3529-6000
> Mobile: +55 11 9287-5646
> JBoss, a division of Red Hat @ www.jboss.com
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17 years, 7 months
Writing a business-Rule (Promod George)
by pramod george
Hi.
I'm new to Drools and also to this group.
Can anyone give me some pointers on how
to write a business rule in a drl language?
Ie:- any pdf or link that talks about
(in depth) analysing a business scenario
and then converting it into a drl format?
Thank you.
-Promod
17 years, 7 months
Questions on building from source of 4.0.7
by Brett M. Bergquist
What is the correct way to get the source for the 4.0.7 release. I
followed the directions in the documentation and used the SVN repository:
http://anonsvn.labs.jboss.com/labs/jbossrules/trunk/
but is there some release tag that I should be using to ensure that the source that I retrieve matches the 4.0.7 bin release?
A second question, when I build from this source, I get 3 tests failing. I can build with a "-Dmaven.skip.test" but should there be tests failing?
17 years, 7 months
Compilation failed on BRMS with multi-consequence DSL phrase
by Benjamin J McMillan
Hello all,
I have a single DSL phrase that performs 2 actions, delimited by a
semicolon. This compiles and works fine under Eclipse. However, when I
uploaded the same DSL to the BRMS and rewrote the same rule that uses
this phrase, rule validation failed:
Unable to build expression for 'consequence': Failed to compile: 1
compilation error(s) ' modify(svc) { addBenefit( [...] ) }; insert(new
Decision( [...] )); '
( "[ ... ]" is sanitized for our protection )
The DSL phrase:
[consequence][]Do {p1} to {p2};=modify(svc) { addBenefit("{p1}") };
insert(new Decision(c, "{p2}"));
Note that in our DSL the RHS of the phrase does not include a line
break.
Is this a bug? Or are we just doing something wrong? Or can't the BRMS
handle this (again, Eclipse can)?
Any help is greatly appreciated.
Cheers,
Ben
17 years, 7 months
Java vs mvel dialects
by Krishna Satya
Hi, I am trying to understand the difference in how drl rules are expressed
via the java or mvel dialects. Looking at the drools-examples it is not
exactly clear. I was looking at the PetStore.drl which seems to specify the
dialects for various rules using both java and mvel. Are there any
references to examples which showcase a rule that is expressed both through
java and mvel dialects so it is clear what the differences are. The rules
in the PetStore.drl which specify java or mvel syntactically seem to look
the same.
Also, are there any general suggestions as to when a rule author should use
the java or the mvel dialect.
Thanks.
- K
17 years, 7 months
Salience not working
by sridhar123
rule A
Salience 10
when
$data : MyFact( $anotherObj )
then
$anotherObj.setDiscard(true)
rule B
Salience 5
when
eval ($anotherObj.isDiscard() == true)
then
...
I am trying to get Rule A executed before Rule B. So when condition in Rule
B is valid. However i dont see "Saliene" has any effect. How else i can do
the above?
thank you
--
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17 years, 7 months
