[Zope] Zope 2.7.3 Memory Leaks

[Dieter Maurer]

Andy Yates wrote at 2005-1-3 13:49 -0600:
> ...
>After flushing main and temporary
> ...
>OK so the numbers are small.  This means there is no leak right?

Right -- at least not the usually leaks.

The reference count list shows you only reference counts for
instances (and not elementary types). You might build leaking cycles
consisting only of elementary types -- but this is quite
unlikely.

Also, Python never releases integer objects it has constructed.
Thus, once you iterated from 0 to 4 G, you have several GB
of integer objects -- but it is unlikely that you do this...

> It may
>not be leaking, but python still consumes all available memory and dies
>unless I restart Zope every few days. ;-)

You did this flushing and looking at the reference counts in
a process that already had run for several days (and therefore was quite
huge)?


Do you use C extensions that create non-Python objects (and
therefore do not have reference counts and show up in the list)?
Maybe, such a C extension is leaking.


There are tools to analyse memory leaks (and other memory related problems).
Once, I have use the (commercial and expensive!) "purify".
Andreas (Jung) told me that there are free open source tools
for this purpose around. Unfortunately, I forgot the details
(I only create standard leaks :-)

> ...
>Maximum number of subobjects is infinite (0)
>Data object timeout is 45 minutes

Are your sessions huge?
Usually, they are stored as pickles in RAM.
If they were huge, some thousands of sessions might
consume a considerable amount of RAM. You would not see
them in the reference counts because Pickles are strings
and you see only instances.


-- 
Dieter