Applications Messaging Standard

Doug Tody dtody at nrao.edu
Thu Feb 15 13:07:18 PST 2007


On Thu, 15 Feb 2007, John Taylor wrote:

> Hi Doug,
> Sorry if my terminology clouded the issue,  though I do believe this is an 
> issue of user-friendliness.
> As I see it, either the messaging infrastructure always sits at a known 
> location, or its connection info must be made known to any clients.

Or both; see for example my recent mail in reply to Mark.

Files are fine for persistent storage or for configuration info such as
saving user preferences, but are lousy for interprocess communication.
IP (sockets) on the other hand, were designed for this purpose.
A simple solution is to provide a well-known port for discovery
(basically just a simple keyword-value cache; back it up with an
environment variable or whatever to config the address)), and hand-off
to dynamically allocated ports for session stuff.  This can all be done
at the protocol level without an API, is universally available, and is
really not much more complex than using a file.  Probably less complex,
when you consider the subtle issues that files have for this purpose.

Ultimately you probably need both: IP for interprocess communication,
and files (or possibly the registry on a Windows platform) for
configuration and saving user preferences.

 	- Doug



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