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

[sean.upton@uniontrib.com]

I suppose that one issue is that packing in DirectoryStorage uses snapshots
so that using something like rsync or cpio+find+nfs for incremental
backup/replication to a peer ZSS would need to use snapshots.  You can't do
this while packing though, because packing uses snapshots.  So a replication
tool that uses normal history isn't prohibited during packing.

This is how I understand this, but Toby may have a different (and likely
more correct - and certainly more informed) explanation.

Sean

-----Original Message-----
From: Paul Winkler [mailto:pw_lists@slinkp.com]
Sent: Wednesday, February 12, 2003 5:53 PM
To: zope@zope.org
Subject: Re: [Zope] replication (was Zope: 5.4, jboss 0.3 million hits
with google)


On Thu, Feb 13, 2003 at 09:01:37AM +0800, Bakhtiar A Hamid wrote:
> On Thursday 13 February 2003 04:51, Paul Winkler wrote:
> > On Wed, Feb 12, 2003 at 11:26:05AM -0800, Jack Park wrote:
> > > ... Theoretically speaking, JBoss has tackled the scalability
> > > issues. I have yet to find that Zope has done the same.
> >
> > A ZEO cluster running behind Squid...
> > if that's not fault-tolerant or distributed enough,
> > use DirectoryStorage and have automated replication of multiple ZEO
> > clusters. Theoretically this could scale to really enormous amounts of
data
> > serving enormous numbers of users.
> 
> how can we replicate with DirStorage?  would you mind doing a little brain

> dump?  with rsync?

I am not really the person to ask, as I haven't actually done it.
But here's the official way to do it as of version 1.1: 
http://dirstorage.sourceforge.net/replica.html

I would naively assume that you *should* be able to replicate by
1) putting the "master" into snapshot mode
2) running rsync
3) taking the "master" out of snapshot mode

... but there may be hidden issues with that; I would kind of
assume so, since Toby Dickenson bothered to write the replication
tool.  Toby, are you reading this? Care to comment?


-- 

Paul Winkler
http://www.slinkp.com
Look! Up in the sky! It's YET ANOTHER KATANA ROGERWILCO!
(random hero from isometric.spaceninja.com)

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