[Zope] Q: How to manage a long-running external program

[Evan Simpson]

I have an External Method (which fetches, grinds up, and mixes data from
several URLs) which can take 30 secs or more to run.  Since Zope isn't
concurrent yet, it blocks all other requests for an unacceptably long
period.

I vaguely remember reading about a way to return a "Processing request" page
immediately, then have the client automatically retry at intervals until the
final response is ready.  The Method could easily be made into an external
program, but then I'm not really sure of the best way to launch and wait for
completion of an external program from Zope.

I realize that this is really a general web server question more than a Zope
question, but it might be nice to have a Product which can handle this
situation automatically.

Thanks,
Evan Simpson