[ZODB-Dev] When will the Data.fs.index will be touched

[Jim Fulton]

On Thu, Dec 9, 2010 at 5:25 AM, Axel Gerke <axel.gerke at web.de> wrote:
> Hi,
>
> I'm Axel Gerke, yet another zope developer. My question is: Under what circumstances will the Data.fs.index be touched (i.e. its timestamp changes)?
> After consulting Andreas Jung, he can only remember, the file will be only touched @ startup or shutdown. But we see that the file's timestamp changed at runtime.
> Can someone tell me at which operations the Data.fs.index will be touched?

It's written on shutdown, pack and on startup if there was no index or
if the index was out of date.

In some versions of ZODB, the index was periodically written after a
certain amount of growth although the algorithm was flawed in such a
way that when the database grew large, the index was almost never
written due to growth.

Note before ZODB 3.10, it could take a long time to write an index for
a large database.  It could take so long that zdaemon, with it's
default timeout setting would do a hard kill of the process before it
had a chance to finish writing an index.  In ZODB 3.10, index writing
now only takes a few seconds.  If you're using ZODB 3.9 or earlier,
you should use the zdaemon backoff-limit option to configure zdaemon
to wait much longer before doing a hard kill.

Jim

--
Jim Fulton