Applications Messaging Standard

[Doug Tody]

Hi Al. -

I guess I agree that a simple peer-to-peer interface (basically just
a socket connection with some protocol on top) is a special case.
However a hub and a bus differ mostly in terms of efficiency, not
semantics.  The more general messaging infrastructures support all
the options with various degrees of performance.

So, a critical agreement is on whether having *only* peer-to-peer is
sufficient.  Even if this agreed (I hope not, as producer/consumer
messaging is fundamental, and be implemented without some
infrastructure), then the interface should be formally defined so
that this can be layered upon a more general implementation.

 	- Doug


On Sat, 17 Feb 2007, Alasdair Allan wrote:

> Doug Tody wrote:
>> If we try to think about this a bit more formally, what we need to
>> define is merely an "interface" (e.g., in the sense of a modern
>> language such as Java etc.) which provides certain well-defined
>> operations with well-defined semantics.  An "implementation" like
>> the PLASTIC hub merely implements this interface.  So long as some
>> software implements the interface in a compliant fashion, it doesn't
>> matter how it is implemented.
>
> Well no. Are we going to use a hierarchical, peer-to-peer or hub based 
> system? Before we decide on the message format, protocol for exchanging the 
> messages and a transport standards for exchanging them over, then we really 
> have to decide on what sort of topology we're talking about. There are 
> fundamental differences between building a standard around an entirely 
> peer-to-peer architecture, than building one which uses a central hub!
>
> Al.
>