[Zope-dev] copy & paste 'leakage'

[Matthew T. Kromer]

Martijn Faassen wrote:

>Hey,
>
>I'm running into a weird problem I'm not sure how to tackle. I've
>noticed that under some circumstances it takes a long time to copy
>and paste a ParsedXML object. This seems to happen in a clean Zope,
>at least in the Zope root, though it doesn't seem to happen in folders.
>I've also had it happen in Folderish objects in an app, though *sometimes*
>the problem wouldn't occur. Quite peculiar.
>
>I noticed that it wasn't only slow; it was generated huge amounts of
>useless volume for the ZODB as seen in the database management screen;
>objects a couple of K big generally cause a meg or two of leak when
>the copy process is 'slow'.
>
>I concluded the copy process is this slow because Zope is somehow
>copying far more data than intended.
>
>But I don't know what; I need to get a clue in order to tackle this problem,
>and this is as far as I've gotten. I've speculated somekind of weird
>acquisition wrapper issues may be involved (certainly possible with ParsedXML),
>which cause other objects to be copied, or possibly the same XML nodes
>to be copied, multiple times, even though I can't find them. But perhaps
>someone else has run into this problem before and can give me some idea
>on where to start looking.
>
>Regards,
>
>Martijn
>

Martijn, under Zope 2.5, there's a utilites/ZODBTools/fstest.py program 
which can be used to take a look at your Data.fs file -- if you run it 
 with -v -v (two verbose flags) it will print a line for each object in 
every transaction.

If you look at the tail end of the output, you should be seeing the 
transactions performed last.  You should be able to do some degree of 
differenentiation based on that to figure out the volume of objects 
being copied in the FileStorage.

-- 
Matt Kromer
Zope Corporation  http://www.zope.com/