[Zope] Memory management problems

Peter Millar peter.millar at parasyn.com.au
Tue Apr 19 20:27:31 EDT 2005


I have a serious memory problem.  And would like to hear from anyone who
has large image files being served up to a large number of simultaneous
user base.

I am running plone 2.0, zope 2.7.3, python 2.3.3, on windows 2003 server
with 1.5 GB RAM.

I have a 1MB image.  I have created a little script to copy and paste
this image.  To do it 50 times takes 6 minutes and uses up 300 MB of
RAM.  If I then view the folder that contains all the images and start
viewing the zpt that serves a single image it takes 40 seconds to a
minute 20 and chews up approx 2-5MB.  If I then get a few other machines
to request the same image at the same time, it takes 20seconds for the
first machine, 40 seconds for the next machine and 1 min for the next
machine and another 20 MB of ram has been chewed up.  Each time I go to
serve a page my CPU usage jumps to 50% for the minute or so.

After doing this over and over for a few minutes sees my machine has no
RAM left.  The only way to recover is to restart zope.

My question after all of this is how in the world can anyone seriously
use plone/zope in a real world scenario with potentially millions of
users accessing a site viewing content if you have to restart your zope
service every minute.

I have spent the past two days looking at all sorts of cacheing ideas,
session ideas etc.

Is there some magic that I need to apply for this to work like any
number of web image viewers.  Or is it a case of throwing 100GB of Ram
at the machine.

____________________________________________ 
Peter Millar 





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