[Zope] External methods & persistance and thread safety

Paul Winkler pw_lists@slinkp.com
Wed, 4 Jun 2003 10:00:31 -0400

On Wed, Jun 04, 2003 at 12:51:39AM -0700, Dennis Allison wrote:
> I have a Zope that is being used for content development.  Much of the
> content is maintained in the local file system (e.g. CVS, temporary files,
> and the like).  Some of the operations can take a bit of time.  And I have
> a number of folks banging on the system at the same time.
> Much of the heavy lifiting is done by python external methods and calls to 
> systems programs through the os.system() method.  It all works swimmingly 
> but for a couple of instances of anomolous behavior--the wrong file
> getting written, for example. It could be a program error, but I don't
> think so.  I'm wondering if I am running afoul of some persistance or
> threading problem.   

I'm no thread guru, but that certainly sounds like a threading issue.  
Hard to say without knowing your external method code, what system
programs you run, what arguments you give them...  Can you give us
some idea of what these external methods do?

> (And to make things suitably complex, this is all
> running on a dual processor machine.)

i dunno if that matters - python never uses more than one CPU at a time
due to the global interpreter lock.  OTOH, if you had two zope instances 
using zeo... might be an issue.


Paul Winkler
(random hero from isometric.spaceninja.com)