[ZODB-Dev] Writeperformance for different storages

Toby Dickenson tdickenson@geminidataloggers.com
Wed, 18 Dec 2002 14:13:33 +0000


On Wednesday 18 December 2002 1:38 pm, Andreas Jung wrote:
> --On Mittwoch, 18. Dezember 2002 08:25 -0500 "Barry A. Warsaw"
>
> <barry@zope.com> wrote:
> > That's not bad actually, considering all the overhead (and benefits)
> > of BerkeleyDB, but that does require gobs of memory and at least two
> > independent disk controllers

I know the BDB documentation says it is a good thing, but did you measure=
=20
whether the independant controllers actually made a difference? to reads =
or=20
writes? I would not expect that ZODB (particularly under ZEO) has enough=20
concurrency for this to make a difference.

(If it makes a difference for BDB, I might consider resurrecting a plan t=
o=20
stripe a DirectoryStorage across directories on multiple controllers)

> >  (one for the BDB log files and one for
> > the data).  Plus some system-specific tuning of cachesizes, etc.
>
> So your conclusion is: there is nothing faster than FileStorage? :-)

Its hard to imagine a storage writing any fewer bytes to disk, or writing=
 them=20
in a way that is any faster to fsync. I think FileStorage has unbeatable=20
write performance.

Semi-serious suggestion: DemoStorage ?


--=20
Toby Dickenson
http://www.geminidataloggers.com/people/tdickenson