[ZODB-Dev] Missing Content

[Dieter Maurer]

Michael Havard wrote at 2006-5-1 06:57 -0500:
>Python 2.3.5, Zope 2.8.4, Plone 2.1.2, and a host of other products. ZEO
>configuration. Persistent disk caching is on.
>
>Yesterday everything was fine. All the content was there and accessible.
>Today I try to log in and the server doesn't respond. I go out and restart
>the zope client, still no response. I restart the zeo server and the site
>delivers content. Problem! The content is from two weeks ago. All of the
>content from the last 16 days is missing.

I have seen such a behaviour when a colleague moved the storage file
without stopping the ZEO server and then copied a new storage file
at the old place.

  Under *nix, moving/deleting a file does not affect processes
  which have this file opened. Such processes continue to
  work with the open file.


In the case described above, the ZEO server continued to use
the old storage file and ignored the copy. Of course, as soon
as the ZEO server was restarted, the new ZEO server used the copy --
and did not see anything that went into the moved away storage file.

In our case, the moved file was still present and we could recover
all modifications. If we had removed the file instead of moving it,
then only experts able to restore deleted files would have been able
to get our modifications back.

-- 
Dieter