[Zope] Memory and Large Zope Page Templates

[Santi Camps]

Hi all,

I'm trying to understand some questions about Zope and Memory 
management.   I've configured a Zope with minimal Cache settings: 100 
objects of cache, 4 threads and 20 Mb of ZEO Cache.   The Storage is a 
DirectoryStorage of 4Gb.   Monitoring the Zope process, all is running 
fine: it takes about 30 Mb of RAM.  I've see that just 2 of the threads 
are working.

The problem begins when I execute a report.  The report is a 
PageTemplateFile that calls a method to obtain a list of processed 
results and send them to the user.   It takes some time of process, but 
it works fine.   What I don't understand is why, after this report,  
Zope is taking 120 Mb of RAM !!  Too much for the cache I have. 

I've look for for a memory leak, showing refcounts in method like this:

    def _get_refcounts(self):
        import sys
        import types
        d = {}
        sys.modules
        # collect all classes
        for m in sys.modules.values():
            for sym in dir(m):
                o = getattr (m, sym)
                if type(o) is types.ClassType:
                    d[o] = sys.getrefcount(o)
        # sort by refcount
        pairs = map (lambda x: (x[1],x[0]), d.items())
        pairs.sort()
        pairs.reverse()
        return pairs

But there is nothing rare.   I can see how the refcounts of some objects 
are heavely incresed during the process of the report, but when finished 
they are freed.  But RAM of the Zope process don't decrease.  

Anybody have an explanation ?  It's recomended to run this kind of 
reports in a new process ?  In this case, there are any products to help 
this way ?

Thanks in advance

Santi Camps