[rules-users] drools expert: memory issues

[Wolfgang Laun]

The figures (+300MB) you quote are frightening, and it would be *very*
interesting to learn what sort of rules causes this excessive amount
of heap usage. Could you post typical patterns - if they are
generated, there ought to be - and guestimates w.r,t, their relative
frequencies?

-W


On 3/30/10, miguel machado <mls.machado at gmail.com> wrote:
> hi again,
>
> On 30 Mar 2010, at 18:32, Edson Tirelli <ed.tirelli at gmail.com> wrote:
>
>    I am not sure I understand what you are doing when you say:
>
>> Every X seconds I collect the available facts and call fireAllRules() +
> dispose(), **always within the same session**.
> (emphasis is mine)
>
> i meant that i keep using the same object, i just create one stateful
> session throughout the program execution.
>
>    Compilation indeed uses more memory, but you can compile once and reuse
> the kbase.
>
>
> exactly, i'm doing that, but it's a +700 rule file and its taking too much
> memory. Is there anything i can do to push it down a little bit? i wouldn't
> mind slowing it down to reduce memory footprint.
>
> Also, if you are calling dispose, I guess you are running stateful sessions.
> Maybe you can give us a more detailed description of your
> session/data/application lifecycle?
>
> Sure, i'll try. So i have this thread which initializes by reading the rule
> base from a drl file. It then creates a stateful session from it and enters
> a lifecycle in which it goes to sleep and only when some other thread wakes
> it up, it collects and inserts some facts (usually 2,3 or 4..) into the
> session and fire all rules. It's basically this. What i'm very concerned
> about is the amount of RAM memory the whole program is consuming. I must
> find a way to reduce some of it, because the rule file is being prepared by
> an external program and i have no control over the number of rules i might
> get. If i test it with a little over 700 rules, it reaches +300Mb which is a
> lot.
>
> Maybe the rules are too complex? Shall i try to make them simpler (how)?
> what are the big memory hogs when it comes to loading a DRL file to the
> knowledge base? From what i've been testing, it doesn't even matter which
> rules you will actually need, it just loads the entire DRL file with no
> respect to the future activations, am i right? Is there any other aspect i
> should take in mind or maybe other approach?
>
> _ miguel
>