Leaking HTTP requests (was: RE: [Zope] LeakingAcquisition.ImplicitAcquirerWrapper)

[Brian Lloyd]

Zope.org doesn't use Localizer (or Archetypes - another thing 
that has come up in this thread).

In our experience, this sort of thing has almost always turned
out to be a wrapped object ending up in the REQUEST or a wrapped 
object holding onto a request for some reason.

I've attached a quick product you can drop in to test that 
theory on your own instance (just make a directory 
Products/LeakBGone and drop this __init__.py into it and 
restart).

If it fixes the leak, we can extend it to do some logging and 
try to figure out the root cause. I'll try it out on zope.org 
as soon as I'm able. 


Brian Lloyd        brian at zope.com
V.P. Engineering   540.361.1716              
Zope Corporation   http://www.zope.com 


> -----Original Message-----
> From: zope-bounces+brian=zope.com at zope.org
> [mailto:zope-bounces+brian=zope.com at zope.org]On Behalf Of Stefan H.
> Holek
> Sent: Thursday, May 13, 2004 3:14 PM
> To: Brian Lloyd
> Cc: Jean-Francois.Doyon at CCRS.NRCan.gc.ca; zope at zope.org
> Subject: Re: Leaking HTTP requests (was: RE: [Zope]
> LeakingAcquisition.ImplicitAcquirerWrapper)
> 
> 
> Does zope.org use Localizer or some type of "global request" patch?
> 
> Stefan
> 
> 
> On Donnerstag, Mai 13, 2004, at 21:42 Europe/Vienna, Brian Lloyd wrote:
> 
> > FWIW - zope.org is suffering hugely from this as well, so
> > I'm following this thread eagerly ;)
> --
> The time has come to start talking about whether the emperor is as well
> dressed as we are supposed to think he is.               /Pete McBreen/
> 
> 
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##############################################################################
#
# Copyright (c) 2003 Zope Corporation and Contributors. All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################

"""LeakBGone

  An experimental monkey-patch product that tries to ensure that no 
  unexpected objects (especially acquisition-wrapped objects) remain 
  on the REQUEST object that could cause a circular reference (and 
  thus a memory leak). It is still bad form to store such objects in 
  a request, whether this hack works or not ;)

"""

from ZPublisher.HTTPRequest import HTTPRequest
from zLOG import LOG, INFO

def close(self):
    """Replace the standard REQUEST.close method with one that
       explicitly wipes out everything and takes no prisoners."""

    # If this works ok, next step is to add some logging whenever
    # we find a wrapped object, so that we can stub out the cause.

    names = self.__dict__.keys()
    for name in names:
        value = getattr(self, name)
        clear = getattr(value, 'clear', None)
        if clear is not None and callable(clear):
            clear()
        setattr(self, name, None)
        value = None




def initialize(context):
    HTTPRequest.close = close
    LOG('LeakBGone', INFO, 'LeakBGone initialized')