At 10:23 AM 10/12/01 -0400, Paul Everitt wrote:
Wow, this is one hell of a thread. :^)
FWIW, Grisha put a Bobo publisher in mod_python a couple of years ago. Thus, if you like ZPublisher-style processing, you can do it in Apache via mod_python.
Personally, I prefer to keep a process boundary between Apache and my apps, for both safety and security. Usually they're running as different users, for one thing. We've been very pleased with FastCGI performance using mod_fcgi, so I don't see a whole lot to be gained by using mod_python. Another interesting factor that can affect performance is that we usually run many pre-forked Apache child processes, but rarely have more than 2 or 3 application processes. Using mod_python would probably impact memory usage adversely, since there would then be in effect a larger "application pool". A somewhat simplistic analysis of memory usage in the different approaches: O = Fixed application overhead (e.g. Python modules) D = Application dynamic data A = size of an Apache process P = Memory used for a python interpreter (if the OS shares executable segments, ignore the code size, as it will be a constant for all approaches and thus irrelevant for comparison purposes. In that case consider P will be the interpreter's data size) n = Number of threads or processes in the app server pool s = Number of Apache servers Zope w/Apache frontend = P + O + D*n + A*s mod_python = (P+O+D)*s + A*s ZLite = (P+O+D)*n + A*s Since "n" is usually smaller than "s", the ZLite approach uses considerably less memory than the mod_python approach, but can be faster than the Zope+Apache combination on multi-processor machines when the Python interpreter lock is an issue, at an extra cost of only (P+O)*(n-1). In our situations, that usually amounts to at most 2 or 3 times P+O, which is a small price to pay for also being able to ignore all threading issues.