[Zope] Zope Myths?

[tomas@fabula.de]

On Thu, Sep 12, 2002 at 11:12:27AM -0600, Bill Anderson wrote:
> On Thu, 2002-09-12 at 00:21, tomas@fabula.de wrote:
> > On Wed, Sep 11, 2002 at 03:46:43PM -0700, sean.upton@uniontrib.com wrote:

[Big hardware vs. replication]

> Well, in that case, your network is a single point of failure, too. :^)

Assuming just one network, assuming just one connectivity provider.
Problem is that replication solutions depend heavyly on the type of
application (slowly changing sets of files being the easiest and
rapidly changing data sets with complex interdependencies (e.g.
high-volume databases) the hardest.

> Expensive, well that depend son what you are doing. For under 35000 you
> can have just shy of a 1TB of file space, with snapshot capability,
> multi-machine fail over, and a whole lot more. That cost includes two
> machines running Linux with fail over. It depends on your needs, and
> your uptime/availability requirements.

...or you can have ten cheapo off the shelf servers hosted at wildly
different places... (OK, it's more like 0.5TB then ;)

> For example, if you are running a site like cbsnewyork.com, 25-35 grand
> is not that much. If you are running a small site, then you don't need
> it. My point was that it (it being ZEO/ZODB/ZOPE) _can_ scale to that.
> I've done it.
> 
[...]
> 
> Well, speaking as a former tester of SAN technology, it would appear
> things have changed dramatically since your experiences. :)
> 

Yes, but this was mainly my point: if you have access to knowledge
and experience with those things -- then you may go for it. If
you don't... it's just a point against it.

> The configuration/setup is essentially the same as with SCSI, in fact,
> Fiber channel uses the SCSI subsystem in the OS. The underlying system
> is as robust as the SCSI system, since it is SCSI just over a different
> medium.
> 
> 
[RAID system doing funny things]
> 
> I've never seen this with the Fiber Channel Arrays I dealt with. But
> then again, they had two or more controllers. :^)

Of course not -- but I take that you *know* what you are doing. This
vendor didn't (at some point I realized that), but heck, it wasn't my
job, I had enough on the plate myself.

[...]

> Same thing with fibre channel SAN tech, the range is measured in miles.
> I know of several SANs that are spread over multiple states. You can
> literally have a fail over datacenter.

Yes. It's a tradeoff. I just wanted to point out that experience with
those things is one of the points to consider (besides application type,
requirements and cost).

It'd be interesting to know (I'm not a Zope guy) how well Zope as an
application would play in each camp.

Thanks
-- tomas