[rules-users] Sessions, WorkingMemory, Long lived facts

[David Sinclair]

You sorta understood it, it was probably my description that was lacking :)

My application has two kinds of objects, Resident objects and Transient
objects.

   1. Transient objects are per-request objects that will get asserted into
   the rules engine. At the end of the request they go away
   2. Resident objects are application scoped objects that get lazily loaded
   into memory and live beyond the scope of each request


What I would "ideally" like to do is the following

- Create a RuleBase with no facts in it
- Create Sessions from said rule base
- Assert transient objects into memory, which may cause  some resident
objects to be loaded
- Retract all transient objects from memory, but leave the resident objects

Now I could easily do that with 2 interfaces, ResidentObject and
TransientObject, and retract all transients after each fireAllRules(), but
that would also mean i need to use a single Session for the entire lifetime
of the application, right? What I would really like to do is to be able to
"seed" the RuleBase with initial facts that are visible from all sessions.

hope that made more sense

dave


On Mon, Oct 13, 2008 at 4:01 PM, Edson Tirelli <tirelli at post.com> wrote:

>
>    If I understood your question,
>
>    Drools 4 -> use "from" to load them on demand for your rules
>    Drools 5 -> you can do the same, or create a session, pre-load it and
> serialize it to disk or an in-memory binary cache... now, for each request
> from your application, instead of creating a new session, de-serialize the
> session from your disk (or in-memory cache) and use it. Please note that you
> are doing nothing more than clone-by-serialization for the preloaded
> session, if you use this strategy.
>
>    []s
>    Edson
>
> 2008/10/13 David Sinclair <dsinclair at chariotsolutions.com>
>
>> I have a question concerning facts. I have a service based application
>>
>> XML IN -> Business Objects -> Rule Processing -> Business Objects -> XML
>> OUT
>>
>> Pretty straightforward.
>> In the rule processing I will lazily load objects into WorkingMemory that
>> drive some of the business rules. For instance, if a new Windows
>> Server(Business Object) is installed, ensure its OS is only Windows Server
>> 2007 (lazily loaded DB object).
>>
>> What I would like to do is be able to either preload the working memory
>> with this data, or preferably, lazily load the data. So my question is how
>> do you place facts into working memory when you create a new session each
>> time without having to assert them everytime? Or this that a stupid
>> question...Should the question be, since working memory/sessions aren't
>> thread safe, i.e. one can't be shared by everyone, what is the best way to
>> place long lived facts into memory of all sessions?
>>
>> thanks
>>
>> dave
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>>
>
>
> --
>  Edson Tirelli
>  JBoss Drools Core Development
>  JBoss, a division of Red Hat @ www.jboss.com
>
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>
>
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