I have a Plone site that has begun to randomly serve up the wrong content. Any given content suddenly shows something else. Sometimes a JPEG loads a stylesheet instead or a stylesheet loads as a page or a page as an image. The images move around, some times our site logo shows a bullet, or one of the other site images. Fiddler shows the wrong content in the response, the apache logs show the content type of the incorrect file (so if the an image loads in place of a style sheet, apache shows that).

We thought mod_proxy was the source of our grief, but we get the problem hitting Zope directly. I never get the wrong content using the Medusa Monitor to repeatedly hit the content. I do see ConflictErrors in the instance.log file, and they seem to be correlated to the problem, but not 100%.

ZPublisher.Conflict ConflictError at \path\to\object: database conflict error (oid 0x3586, class BTrees._OIBTree.OIBTree, serial this txn started with blah, serial currently committed blah) (X conflicts (0 unresolved) since startup blah)

I pulled that off the web, it's not from our logs, but it's the same message. This may be a red herring, it sounds like those messages are normal.

We've updated to the 3.3.5, same problems.

I'm at a loss. I'm wondering if there a good way to intercept what is being served? Secondly, is there a way to increase the verbosity of the access log to included the content-type?

I've even seen the problem manifest in ZMI. It happens more often when we're authenticated. Sometimes it can take a thousand reloads to see the problem, other times it happens in different ways every time we reload.

I believe we've seen this problem for a couple years, but it was very intermittent, a page would show the content of a GIF, then a reload later wouldn't happen for a long time. Now it's a huge problem.