[ZODB-Dev] RE: [Zope-CMF] Big CMF sites / Storage

[sean.upton@uniontrib.com]

I've posted this to ZODB-dev for further discussion about scaling big
ZODBs... a bit of background on my most current project: a CMF site with
potential for 1million+ objects.

Regarding hardware... I'm trying to forecast what to buy, and this is what
I'm guessing at the moment...  All boxes are likely to be Dual Athlon MP
boxes (1.2 & 1.56 GHz), with likely to be 1GB on Zope clients and 3GB on the
ZSS box; the ZSS will be running a RAID10 of 4 10kRPM drives (via Mylex 170
16MB cache).  The ZEO client cache will be run on a software RAID0 of two
volumes on 7200RPM IDE disks...

If I understand correctly, FileStorage might make more sense from a
performance perspective, provided you apply the recent index patches and
have LFS support in your kernel/fs/python.  As far as RAM goes, my informal
and purely anecdotal experience is that doing a Catalog reindex of about
330k simple objects consumed up to about 500MB or RAM (that's for
Zope+FileStorage with heavy use of subtransactions; I haven't tested that
application with my ZEO setup yet), and I can just imagine what millions
would consume.  Also, if I understand correctly, the new index patches will
yield a savings of at least 14 bytes an object, which would help a bit
(likely more noticeable in the case of a ZSS).

I'm interested in getting perspectives on what kind of hardware and Storage
implementation choices people think are best for large and heavily accessed
ZODBs (HA/replication options are also something on my radar, but I'm trying
to answer the question of performance / scalability first)...

Any thoughts would be appreciated...

Thanks,
Sean

-----Original Message-----
From: Chris Withers [mailto:chrisw@nipltd.com]
Sent: Wednesday, January 30, 2002 2:42 PM
To: sean.upton@uniontrib.com
Cc: Zope-CMF@zope.org
Subject: Re: [Zope-CMF] Big CMF sites / Storage


sean.upton@uniontrib.com wrote:
> 
> Chris, you've used both FileStorage and BerkeleyStorage for big ODBs,
right?
> ...for a large DB, which has scaled better for you?

Urm, in my rather specialised scenario they both sucked :-(

I would honestly go for FileStorage right now, but the finer points of the
discussion are best had on zodb-dev@zope.org.

good luck, hope ya got plenty-o-RAM :-)

cheers,

Chris