[Zope] replication (was Zope: 5.4, jboss 0.3 million hits with google)

[Paul Winkler]

On Thu, Feb 13, 2003 at 11:18:42AM +0000, Toby Dickenson wrote:
> > I am not really the person to ask, as I haven't actually done it.
> 
> But you know you want to ;-)

How did you know? ;)

(rsync sync strategy snipped)

> That will kinda work, apart from the performance issues mentioned above. Take 
> care over locking on the replica; you dont want replication to restart when 
> the master comes back up after an outage, with the storage still running on 
> the slave.

good point.
 
> The big problem with this is that rsync is not atomic. If the master explodes 
> half way through an rsync then the replica may contain half of the most 
> recent transaction.

what could make the master "explode" if it's in snapshot mode?
catastrophic failure of some kind?
 
> 1.1 might still be in alpha, but I am sure it is more stable than anything 
> based on rsync. As always, I am already using it in production. Replicating 
> once per minute and performing a full check on the replica storage once per 
> hour. It is looking good so far.

Once per MINUTE??? that's better than anything I hoped for.

Dare I ask for a 1.1 timeline? We are very interested in DirectoryStorage
but I know my team won't sign off on running our zodb off of some arbitrary
CVS checkout, it'll have to be a stable release. 
We might go ahead with 1.0 in the meantime since it addresses a number
of our annoyances with FileStorage, and our storage is only growing
and growing....


-- 

Paul Winkler
http://www.slinkp.com
Look! Up in the sky! It's SUBORDINATE POLYTHEI-BUTTER CHURN!
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