Re: Forking to an interactive program under mod_perl

["Alex Beamish" <suppressed>]

On 12/15/06, Jonathan Vanasco <suppressed> wrote:

On Dec 13, 2006, at 1:58 PM, Perrin Harkins wrote:
> However, you could also avoid the problem by running only one
> apache process.

That line got me thinking...

I wouldn't do one apache process -- i'd do an entirely new server.

Make another mod_perl server (or use a twisted python server, cos its
good for stuff like that ) that  ONLY handles ghostscript.  Instead
of talking sockets like in the  other  post, it speaks via http.  It
would be like having a second daemon work on things-- except its not
really a daemon but a gs dedicated mp server.

Your main server works  as-is.   Instead of opening a ghostscript
file, it does  a URL get to tell the other server 'start a new
session'.  Handle everything with URL  commands - why? because  its
way easier than sockets and you can test it using a normal web browser.

The ghostscript-only server is single  process (no children)-- so you
can leave stuff open and just run a periodic check to expire old
documents.

Your main server just stores some session data for the  current state
of the  ghostscript session.  you can

Interesting thinking .. thanks for that.

For simplicity's sake I would prefer to have a single web server with some sort of 'process table' arrangement; I'd like to use a global hash for that, but failing that I may look to SQLite, since we are using that in another area.

And to perrin, thank you, I am able to report that, no, IPC::Run does not appear to work under mod_perl -- I have posted a node at

  http://perlmonks.org/?node_id=590115

with more information. Next step, the more complicated solution.

-- 
Alex Beamish
Toronto, Ontario
aka talexb