Re: Glade :- he distributed Annex

[Toshitaka Kumano <kumano@cl.cilas.net>]

Hi,

Pedro Menendez wrote:
> are there any restrictions regarding the communication in a distributed
> application. I mean clients and server/s on the same LAN and the such. 

As far as I understand, no restriction such as "same LAN", if you mean
"same segment". 
And different segments could be linked by adding appropriate routing ?

Glade just requires the TCP connection is stable, and, of course,
unstable network, by such as a congested router or by ethernet with 
many collisions, could introduce some instability to a Glade application,
if you don't consider some recovery mechanism in your design of the
application.

The distribution annex, a sophisticated RPC, is one thing, and the fault
tolerance of transport layer underlying it is another matter.

In other malicious words, I consider Glade by itself could not be
used for practical, fault tolerant or real-time (deterministic response)
application. This can be "restriction" in your application domain.


> This is the case in MPI, isn't it?

I don't think so. TCP/IP based MPI implementations don't have
such restrictions.

MPI, in its strict meaning, is just a standard (paper) of API and
protocol of presentation/session layer, and the standard says nothing
about its lower layer of implementation. So answer to your question is
"it depends".

For example, our proprietary implementation of MPI is directly
on the link layer of our in-house bus,  without TCP/IP protocol stack,
aimed only for performance, without any routing capability.
In this case, the applications can talk only if they are on "same bus".

-- 
Toshitaka Kumano