[jacorb-developer] Real Time JacORB

[Phil Mesnier]

Hi Kujtim,

Thanks for narrowing the topic. JacORB as it currently exists I think will present a lot of jitter for real time use. First there is the JVM, with its arbitrary garbage collection issues. That can be addressed through tuning. Next there is threading. JacORB is heavily threaded, with thread pools being used to process requests by servants, and also for I/O, waiting for messages. I/O resources are conserved by JacORB by making no more than 1 connection at a time between specific client and server ORBs. This means that multi-threaded clients will suffer queueing if 2 or more threads wish to send concurrent requests to the same server. Response handling is multiplexed, so if the requests are reasonably small, this queuing isn't too bad. 

You may want to consider a hybrid approach where you use a DDS implementation for your data acquisition, and CORBA for the control system.  

Just curious, why are you using JacORB for this task?

Best regards,
Phil

On Jan 7, 2013, at 8:13 AM, Kujtim Hyseni wrote:

> 
> Hi Phil,
> 
> I am building distributed data acquisition and control system based on JacORB. Obviously, it is real timed i.e. I need to estimate the time spent for request/response besides the time to execute the task (but this is not related to JacORB). Initially, I plan to deploy the system in dedicated private network so there are no additional delays in the network. Do you need an extra information?
> 
> Regards,
> Kujtim
> 
>> From: mesnier_p at ociweb.com
>> Date: Mon, 7 Jan 2013 07:50:36 -0600
>> To: jacorb-developer at lists.spline.inf.fu-berlin.de
>> Subject: Re: [jacorb-developer] Real Time JacORB
>> 
>> Hi Kujtim,
>> 
>> You've asked a very broad and general question. Can you restate your question with some context so that we may understand your motivation for asking? For example, do you have some particular use case you are interested in? Perhaps a certain feature set? Or maybe you are targeting some platform and need assistance?
>> 
>> We can have a discussion about RT, but you need to focus the subject a little tighter for us.
>> 
>> Thanks,
>> Phil
>> 
>> On Jan 7, 2013, at 7:28 AM, Kujtim Hyseni wrote:
>> 
>>> 
>>> What about Real Time issues with JacORB?
>>> 
>>> Regards,
>>> Kujtim
>>> 		 	   		  
>>> _______________________________________________
>>> jacorb-developer maillist  -  jacorb-developer at lists.spline.inf.fu-berlin.de
>>> https://lists.spline.inf.fu-berlin.de/mailman/listinfo/jacorb-developer
>> 
>> --
>> Phil Mesnier
>> Principal Software Engineer and Partner,   http://www.ociweb.com
>> Object Computing, Inc.                     +01.314.579.0066 x225
>> 
>> 
>> 
>> 
>> _______________________________________________
>> jacorb-developer maillist  -  jacorb-developer at lists.spline.inf.fu-berlin.de
>> https://lists.spline.inf.fu-berlin.de/mailman/listinfo/jacorb-developer
> 		 	   		  
> _______________________________________________
> jacorb-developer maillist  -  jacorb-developer at lists.spline.inf.fu-berlin.de
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--
Phil Mesnier
Principal Software Engineer and Partner,   http://www.ociweb.com
Object Computing, Inc.                     +01.314.579.0066 x225