SystemError: NULL object passed to Py_BuildValue / IOBTree class

[Travis Miller]

suddenly started getting "SystemError: NULL object passed to Py_BuildValue". the error seemed to occur randomly and frequently in plone sites on no particular type of object.

>>>> event.log
>
> 2004-09-08T18:14:25 ERROR(200) SiteError http://www.example.com/index_html
> Traceback (most recent call last):
> File "/opt/Zope/SoftwareHome272/lib/python/ZPublisher/Publish.py", line 107, in publish
> transactions_manager.commit()
> File "/opt/Zope/SoftwareHome272/lib/python/Zope/App/startup.py", line 222, in commit
> get_transaction().commit()
> File "/opt/Zope/SoftwareHome272/lib/python/ZODB/Transaction.py", line 236, in commit
> ncommitted += self._commit_objects(objects)
> File "/opt/Zope/SoftwareHome272/lib/python/ZODB/Transaction.py", line 351, in _commit_objects
> jar.commit(o, self)
> File "/opt/Zope/SoftwareHome272/lib/python/ZODB/Connection.py", line 411, in commit
> state=object.__getstate__()
> SystemError: NULL object passed to Py_BuildValue

>>>> zmi error_log
>
> Traceback (innermost last):
> Module ZPublisher.Publish, line 107, in publish
> Module Zope.App.startup, line 222, in commit
> Module ZODB.Transaction, line 236, in commit
> Module ZODB.Transaction, line 351, in _commit_objects
> Module ZODB.Connection, line 411, in commit
> - __traceback_info__: (('BTrees.IOBTree', 'IOBTree'), '\x00\x00\x00\x00\x00\x00\x00\n', '')
> SystemError: NULL object passed to Py_BuildValue

following Dieter's suggestion, i logged the object class...

> ------
> 2004-09-08T18:14:25 ERROR(200) ZODB Connection (!) <extension class BTrees.IOBTree.IOBTree at 407877e0>
> ------

our system is a zeo setup with one ZSS and two ZCSs, each on its own box. the ZCSs mount the main/root zodb and several zodbs for individual plone portals. also, the temporary storage is mounted from the ZSS. apache proxy's requests to the ZCSs via "balance" load balancer.

numerous restarts of both ZSS and ZCSs did not correct the problem. errors began occuring immediately after restart.

rebooting all three boxes seemes to have cleared up the problem for now. i will report any new occurances here.

maybe related to collector 1398 - http://zope.org/Collectors/Zope/1398
thread started on <email address hidden> - http://groups.yahoo.com/group/zope/message/136193?threaded=1

thanks,
travis

[Michael Dunstan (michael-elyt)]

FWIW, I have seen this error at least once when load testing sessions. That was before applying the patch to publisher. (Which is now checked into both zope 2.7 and 2.8.) Since then I have yet to see this again. However I was not using ZEO. Also I did see quite a lot of other errors in event.log leading upto this particular one.

[Hans de Wit (hdewit)]

This error occours also in a no ZEO no Plone environemnt.
It started suddenly and from that moment on very frequently
Zope version 2.7.3

[Hanno Schlichting (hannosch)]

Doesn't appear to happening anymore.