Gents, In following to the discussions regarding the leakage zope.org and my site suffer from, I've done some testing, and here's what I've found. First of all, the leak does seem to occur when errors occur. Unlike what Chris suggested, I still suffer from this leak even when I completely remove standard_error_message. How I tested: I use JMeter, and a 99% identical box, dedicated for testing: - RH 7.3 - Python 2.3.3 compiled with ./configure and no options - Zope 2.7 + a variety of products, both custom and well known (CMF, Localizer, etc ...) I look at my error log on my main site to see the types of errors coming up and note the URL/parameters. Such errors include KeyErrors, a RecursionDepth error, a Method-something-or-other error, and so on. I setup JMeter with multiple concurrent threads and run it. Within minutes I can see refcounts growing abnormally on the test server. I then shut everything down and minimize the caches. The following are left around that shouldn't be: Class May 19, 2004 1:52 pm May 19, 2004 2:26 pm Delta Acquisition.ImplicitAcquirerWrapper 1025 1309 +284 ZServer.HTTPResponse.ZServerHTTPResponse 150 247 +97 ZPublisher.BaseRequest.RequestContainer 146 240 +94 ZPublisher.HTTPRequest.HTTPRequest 172 262 +90 Right now I've focused on finding out why the Requests are still around. Using the gc module, I've found that all leaked requests are being held by a dictionary. If I look at said dictionaries, this is what they might look like: {'REQUEST': <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/francais/mapsatoz>}, {'REQUEST': <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/francais/mapsatoz>}, {'REQUEST': <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/english/search/political>}, {'REQUEST': <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/english/search/political>}, {'REQUEST': <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/english/search/political>}, {'REQUEST': <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/english/search/political>}, {'REQUEST': <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/english/search/political>}, {3075: <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/english/maps/peopleandsociety/age/youth/HEAD>, 4100: <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/debug>, 5125: <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/debug>, 6150: <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/english/search/political>, 7175: <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/vh_ site/english/maps/archives/5thedition/other/referencemaps>}, {'REQUEST': <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/debug>}, {'REQUEST': <HTTPRequest, URL=/VirtualHostBase/http/atlastest2.ccrs.nrcan.gc.ca:80/VirtualHostRoot/_vh _site/misc_/WFSAdapter/sqlmethod.gif>} NOTE: I had to hack the __repr__ of HTTPRequest not to use self['URL'] since it seems that attribute is unavailable in a closed request. I use PATH_INFO instead. Most of the time I get the dictionary with the 'REQUEST' key. Those dictionaries with int's as keys are ones generated by the ExternalMethod I use to run the code to debug ... So even errors raised while trying to debug this leaks a dictionary that holds on to the request(s). Said dictionary does not seem to be referred to by anything, at least not anything the gc module can find (gc.get_referrers()). One possible situation is that said dictionary is actually part of the HTTPRequest, and we have a cyclic reference problem. I don't think so however, I've looked at the HTTPRequest instances, and they have nothing in them other than strings, lists, basic dict's and an HTTPResponse instance. I'll take another look to be sure. Next step is too look at the Wrappers and see what they're all about and what's holding them there. I'm hoping this information might give a clue to someone who knows Zope error handling better than I as to what might be the problem here ... Also I understand zope.org suffers from this? :) Based on this information also, I have no reason to believe this is caused by product code ... I have to guess it's a Zope bug? In some ways this is motivating me to reduce the number of errors that could occur, but because ALL errors seems to cause the problem, I ultimately have no control over it and under certain circumstances I suffer heavily from this. 404's alone probably cause this (I'm plannign to test that explicitely as well). Thoughts, suggestions, comments welcome ... Jean-François Doyon Internet Service Development and Systems Support / Spécialiste de dèveloppements internet et soutien technique Canada Centre for Remote Sensing / Centre Canadien de télédétection Natural Resources Canada / Ressources naturelles Canada http://atlas.gc.ca Tel./Tél. : (613) 992-4902 Fax: (613) 947-2410