[Zope] BUG? Strange behaviour of external methods after update

[Dieter Maurer]

A colleague of mine has developed an external method and installed
it as a SiteAccess access rule.
He made a programming error that caused a TypeError exception to
be raised.
He recognized his fault and corrected the external method.

Then, the strange behaviour started:

     The access rule sometimes worked correctly but sometimes
     raised the old TypeError exception.

     I had the impression as if some threads used the
     new and some other threads continued to use
     the old version of the external method.

     We flushed the cache, but to no avail.

My colleague finally reported, that renaming the external method
and reinstalling the access rule fixed the problem.

For me, it looks like a persistence bug.


Problem context:
  * Zope 2.1.6 (sorry for the old version)
  * running in production mode,
    the external method was "refreshed" after modification
    with the "edit" button.


Did you ever see something similar?


Dieter