[Zope] Zsyncer issue

[Paul Winkler]

On Sun, Jul 31, 2005 at 02:34:26PM -0700, Matt Howell wrote:
> so when I saw a posting about
> Zsyncer, I was wondering if there might be a solution
> for keeping two instances of a ZODB synced up.

It's really only intended for manual sync of smallish amounts of 
data.  I would not rely on it for automated mirroring of an entire ZODB,
even if you can cook up some appropriate scripting it is unlikely to be
fast enough for that.

If you need "warm" or "hot" failover of your ZEO server, or you have
such intense performance that you need to load-balance among multiple
live ZEO servers, then the only solution I am aware of is Zope Corp's
ZRS product, which is commercial and AFAICT is priced according the
(probably reasonable) assumption that anyone who really needs it has
pretty deep pockets. See zope.com for more info.

For free / open-source solutions, AFAICT it may be possible to
have automated cold failover, but not multiple live ZEO servers
at once. I'm currently investigating the possibility of automated
cold failover using DirectoryStorage's replication tool to keep the
backup system up to date. (See recent thread "Replication and cold
failover" on dirstorage-users mailing list, find archives at
dirstorage.sf.net).  You could probably do something similar
with Filestorage by using repozo to frequently make incremental
backups, and rsync to copy them to your backup server.


-- 

Paul Winkler
http://www.slinkp.com