[rules-users] Drools 5.2 performance building KnowledgeBase

[Swindells, Thomas]

512mb isn't that big a number, I found that it's the MaxPermSize that was actually
more important to increase with the compilation as a lot of time the usage was
bouncing just underneath the default limit on my system (80mb).
Giving it more headroom reduced the amount of effort the garbage collector was
doing to stop the limit actually being reached.

If you are using maven just add an explicit dependency on mvel in the
dependencyManagement section of your pom:
        <dependency>
                <groupId>org.mvel</groupId>
                <artifactId>mvel2</artifactId>
                <version>2.1.Beta6</version>
        </dependency>

If your using surefire to run your unit tests with maven you may want to add the
appropriate arguments to give the forked jvm more memory, this can be done by
defining the argLine property
<properties>
        <!--Make surefire fork with at least 256mb of heap and 128mb perm gen space-->
        <argLine>-Xmx256m -XX:MaxPermSize=128m</argLine>
</properties>

Thomas
> -----Original Message-----
> From: rules-users-bounces at lists.jboss.org [mailto:rules-users-
> bounces at lists.jboss.org] On Behalf Of darktyco
> Sent: 25 August 2011 03:15
> To: rules-users at lists.jboss.org
> Subject: Re: [rules-users] Drools 5.2 performance building KnowledgeBase
>
> I forgot to answer your other question: I'm on Drools 5.2. I had tried the
> Drools 5.3 Beta 1 distribution but there was no improvement- it seems
> something was fixed specifically in MVEL 2.1 Beta6.
>
> Also, to Thomas: I have to specify -Xmx512m in order to run a pretty bare
> minimum unit test (this does include a Spring application context but it is very
> small) using this Drools setup to run or I will get an OOM Java Heap exception
> within seconds. It is actually kind of strange how quickly the exception is
> thrown. I will double check the 512 figure and get back to you if I can indeed
> get it to run with less memory, I really dislike spreading bad info around. The
> full Webapp needs more than that plus a MaxPermSize increase, but there is
> a lot of other stuff going on in the war.
>
> --
> View this message in context: http://drools.46999.n3.nabble.com/Drools-5-
> 2-performance-building-KnowledgeBase-tp3239746p3282810.html
> Sent from the Drools: User forum mailing list archive at Nabble.com.
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