Hi,
rather than basically human readable name based directories like jndi,
looking for stuff in jini and javaspaces is based on a more
computer-friendly system of entry matching, which sort of like simple SQL
queries. An entry is a special kind of serializable object, which can be
thought of as a tuple + type. Serialization proceeds element by element,
rather than for the object as a whole. Lookups are done by matching an
entry you provide, where a null element means "don't care", and non null
requires an exact match. This for instance is how you query a javaspace:
you ask for matches to an entry you provide.
In jini itself, there is no connection between the jni framework and j2ee
services. I don't know whether anyone has implemented any kind of
connection or how hard it would be. The philosophy is rather different.
I'm afraid you may be reaching the limits of my ability to explain jini.
Besides the javaspaces book, Core Jini by W. Keith Edwards seems like a
good explanation.
Thanks
David Jencks
On 2001.05.08 12:12:15 -0400 [EMAIL PROTECTED] wrote:
>
> Hi David,
>
> Does javaSpace have naming (prefereably directory) jndi support (does it
> inherently possible, and is there already have a decent service
> provider?),
> and is it possible to make portable code between javaSpace and JMS?
>
> I got the impression that JavaSpace is so great, functionally it can be
> JMS, RDBMS and ldap, however, can the code using it be portable with
> those
> guys?
>
> thanks
>
> Kai
>
>
>
>
>
> David Jencks
>
> <[EMAIL PROTECTED]> To:
> [EMAIL PROTECTED]
>
> Sent by: cc:
>
> [EMAIL PROTECTED] Subject: Re:
> [JBoss-user] Advice wanted : Messagedriven Design
> eforge.net
>
>
>
>
>
> 05/08/2001 07:14 AM
>
> Please respond to jboss-user
>
>
>
>
>
>
>
>
>
> Hi,
> I don't have practical experience with what you are suggesting, but are
> you
> sure javaspaces/jini is not a more appropriate framework for your system?
>
> thanks
> david jencks
>
> On 2001.05.08 06:46:11 -0400 [EMAIL PROTECTED] wrote:
> > Hi,
> >
> > I have some questions for experienced jBosS or maybe just ejb experts
> > here, having implemented systems with lots of asynchronous
> messagedriven
> > components.
> >
> > The thing I want to design in here is a network of objects communicting
> > with each other. The concept of message-driven components is just
> > fantastic.
> >
> > I will describe what's going on in my zoo :
> >
> > we have lots of objects in there - lets call them beings. These beings
> > communicate with each other, have different interests, and the whole
> > system is going to serve people in the physical world with different
> > intentions. However it is clear that the objects in the server have one
> > working field - lets say the food industry.
> >
> > The objects in there gather data from different datasources :
> databases,
> > incoming messages, or even clients connecting to the objects. Paul, a
> > food deliverer, may have his own EJB in there gathering requests for
> him
> > and managing them in a way that is most economic for him when he
> drives.
> > His EJB is autonomous, answers requests from other EJBs and just gives
> > them information, and makes deals for Paul, or even IS Paul, whenever
> he
> > is logged in into his EJB.
> >
> > Well - I know thats quite a sick vision.
> >
> > We have lots of objects in there who wont ever be the representation of
> a
> > real-life person. But now come the design issues for this system :
> >
> > I decided to design every object in there like "Paul". So everything in
> > there, or almost everything, will be asynchronous.
> > And every EJB will be able to communicate with nearly every other,
> > asynchronously.
> >
> > Has anyone in here ever put up something similar ?
> >
> > Is there a big trade-off in performance ?
> > (whenever, in a synchronous design, there are several method calls
> > waiting on one object, the ejb server is surely handling them in a
> queue
> > also - so there are surely queues in synchronous as in asynchronous
> > design).
> >
> > What should I watch out for ?
> >
> > My main worry is the performance of a message-driven design. But the
> > possibilities are just fantastic.
> >
> > So my questions are :
> > - how would you see the performance issue ?
> > - if performance is acceptable, do you have any design tips for an
> > asynchronous design ?
> > - have you ever implemented and been running such a system with jboss ?
> > - with a large number of messagedriven objects floating around (the
> > number of objects is larger in the messagedriven design of the system,
> > than in a synchronous design)
> >
> > What would you say ?
> >
> > Best regards, Jubin
> >
> >
> >
> >
> > _______________________________________________
> > JBoss-user mailing list
> > [EMAIL PROTECTED]
> > http://lists.sourceforge.net/lists/listinfo/jboss-user
> >
>
>
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