You did not say if your simulation is running in one JVM or two talking to
each other as if they were separate and networked. On their own, two Jess
engines should interfere with each other even on a single JVM. If they are
directly or indirectly accessing disk files, that might be the point of
contact where they interfere.

"The first engine works fine, but when the second engine tried to make a
ontology update, I get errors such as unable to read/write."

Is it possible that your design has data files for each engine which would
normally be local and private on a distributed system, but are being
inadvertently shared when you run on a single node? 

"The first engine works fine, but when the second engine tried to make a
ontology update"

On its own, Jess is designed to support multiple Rete engines running at
once in separate threads, but you might want to check into Protégé's support
for multiple concurrent updates to a single database. I don't know Protégé,
but your wording implies that your application is writing back through it.

-----Original Message-----
From: #NG BOON KIAT# [mailto:[EMAIL PROTECTED] On Behalf Of #NG
BOON KIAT#
Sent: Wednesday, February 07, 2007 7:31 PM
To: [email protected]
Subject: Multiple JESS engines running in the same application

Hi all,

I'm currently working on a distributed multi-agent simulation system that
uses JESS for behaviour inference. The behaviours are stored inside a
Protege ontology. For each cycle of the simulation, each agent has to update
the ontology, followed by getting the new behaviour from the ontology. 

Ideally, each computer (node) in the system will control a number of agents
as well as have 1 JESS engine. However, during testing of the framework, I
had to simulate the running of 2 nodes on my computer. This means having
more than 1 JESS engine running at the same time. The first engine works
fine, but when the second engine tried to make a ontology update, I get
errors such as unable to read/write.

Is there really no way to have more than 1 JESS engine running at the same
time?


Regards,
Sean Ng.



--------------------------------------------------------------------
To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]'
in the BODY of a message to [EMAIL PROTECTED], NOT to the list
(use your own address!) List problems? Notify [EMAIL PROTECTED]
--------------------------------------------------------------------

Reply via email to