Arnar Lundesgaard writes:
... The problem has been scarily easy to reproduce, and manifests itself whenever multiple persons are working (writing articles etc). As long as only one person is working on the site, it has the expected performance. Not very fast, a few seconds per write operation, but acceptable. However as soon as more people log in and start publishing, we often experience hangs which may last for 10-15 minutes on write operations that usually takes only a few seconds to perform. In this situation Zope doesn't respond to any requests. Maybe, there are "ConflictError"s. When they occur, Zope automatically restarts the requests. I have some doubts that Zope does it in a way that prevents a new "ConflictError" with high probability. On the other hand, it is not too likely, that the automatic repetition increases the time by almost two orders...
Dieter