-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Andreas Krasa wrote: > Hi Tres, > > thank you very much for your reply! > > Am 29.11.09 21:57, schrieb Tres Seaver: >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >>>> ----- Original Message ----- From: "Andreas Krasa" >>>> <andreas.kr...@wu-wien.ac.at> >>>> >>> we're right in the process of tracking down the error outside of ZOPE. >>> >>> We have completely installed a new server from scratch with RHEL 5.4 and >>> have re-installed python 2.4.6 and the latest versions of libxml2 and >>> libxslt there. We double checked the LD config, and made sure that te >>> correct shared objects get loaded (via lsof). >>> >>> We also reinstalled a few other modules that contain C-code (such as >>> python-ldap) which we need for being able to do authenitcation. >>> >>> Unfortunately that didn't really help much. We still experience crashes. >>> >>> Are there any known issues with Zope 2.11.2, LibXML2 and/or LibXSLT that >>> could cause these problems? >>> >>> The only thing we re-used is the Data.fs, which we have to, because >>> we're talking about a production system here. >>> >>> Also note, that we have used excatly the same setup for a long time now, >>> even on the same hardware, without any of these troubles. The problems >>> only started when we switched over to a new (and probably more >>> resource-intensive layout). >>> >>> We're unfortunately still not able to reproduce these crashes. >> Can you set 'ulimit -c' to get a core file, which might at least help >> point to the extension which is to blame (although it may just show the >> "downstream" victim of a heap munge). >> >> What versions of libxml2 / libxslt are you using? How about lxml? > > Yes, we did set the ulimit and were indeed able to produce a coredump > for each crash happening (each having something between 300 and 700 MB). > We tried to debug using "gdb" but unfortunaley they only reveal two > cases when the crashes occur: > > 1) During garbage collection where the gc tries to clean up damaged > python objects > 2) During some "ceval" process, also related to accessing damaged python > objects > > Unfortunately it doesn't reveal what exactly trashes the objects. To us > it seems that this could happen some time earlier before either of the > two processes mentioned above tries to access the objects and crashes ZOPE. > > For now, we don't really see a reproduceable pattern as it seems to be a > somewhat more complex user behavior which leads to this. We were able to > extract a few URLs out of the coredumps but directly accessing those > does nothing. Also the last logged access in the Z2.log before the > coredump triggers nothing, when directly accessing it. > > We're running ZOPE-2.11.2 with an eggified version of ZODB3-3.8.4 plus > libxml2-2.7.6, libxslt-1.1.26 and lxml-2.2.4 now, the crashes still > happen. Previously we've been running with ZOPE-2.11.2, libxml2-2.7.3, > libxslt-1.1.24 and lxml-2.1.5. That also crashed ZOPE occasionally.
Does your application ever use the libxml2 / libxslt Python bindings directly? If so, I would go over that part of your app with a microscope: it is incredibly easy to trigger segfaults from those bindings. If not, then I would look for help on the lxml mailing list. > This only happened since we switched to a new layout (probably in > combination with a few minor Silva updates). By "new layout", to you mean a new site them? If so, how do lxml / libxml2 / lbixslt interact with your application to generate the theme? What is structurally different about the new theme? > We have been using the same system software (RHEL5), hardware, python > version and libxml2/libxslt/lxml versions with our old old layout, where > everything worked fine for years. > > I would be happy to paste any particular gdb outputs if that is of any > help...? I'm afraid that won't help: the GC segfaults indicate somebody is munging the heap way before the segfault is triggered. Tres. - -- =================================================================== Tres Seaver +1 540-429-0999 tsea...@palladion.com Palladion Software "Excellence by Design" http://palladion.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAksT65cACgkQ+gerLs4ltQ5swACgsSuScLIAfFtd1d9TMznaQEeu 7JEAoJBetJHX3KOCbinGlyV5F/7DWjqK =qGv5 -----END PGP SIGNATURE----- _______________________________________________ Zope maillist - Zope@zope.org https://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - https://mail.zope.org/mailman/listinfo/zope-announce https://mail.zope.org/mailman/listinfo/zope-dev )
