[ZODB-Dev] ZEO and blobs: missing tmp file breaks transaction on retry

[Mikko Ohtamaa]

Hi,

We am trying to use BLOBs with ZODB 3.8.4 and ZEO to store images on content
objects using plone.app.namedfile.

We started having more or less random serious issues which break the site.

It looks like that for logged in users, for some page loads, BLOBs are being
rewritten on every request. Somehow transaction is being retried and retry
fails due to missing .tmp file. This is probably fault on our code, but in
any case ZEO/ZODB utterly fails causing nasty exceptions.

(Since I am not a ZODB expert every stated above might be completely false)

Here is the detailed document of the issue:
http://code.google.com/p/dexterity/issues/detail?id=94&colspec=ID%20Type%20Status%20Priority%20Difficulty%20Milestone%20Owner%20Summary

I hope to find advice

1) How to debug ZEO - this was not particularly encouraging:
http://plone.org/documentation/tutorial/debugging-tips-and-tricks-a-real-life-example/oh-server-where-art-thou

2) The actual solution to the problem

3) What might cause it

-Mikko
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.zope.org/pipermail/zodb-dev/attachments/20091112/a6784190/attachment.html