openstack team mailing list archive

[Ed Leafe <ed.leafe@xxxxxxxxxxxxx>]

On Feb 15, 2012, at 10:07 AM, Armando Migliaccio wrote:

> I think you touched the crucial point here: what is exposed to the user and what not. Reading:
> 
> http://wiki.openstack.org/MultiClusterZones#Design
> 
> one would think that zones is a concept exposed to end users. You're saying otherwise; Is it just my misunderstanding or the wiki page is out of sync with the latest developments? If zones are not going to be exposed to the users, what will? Just availability zones?

	Zones *could* be exposed, but that is not intrinsic to their design. Availability zones could be designated as a particular level of nesting of the overall zone design, such as a particular region, and users could specify the AZ they want their instance to be provisioned in. But a region might have several data centers, each of which could be a zone, and individual DCs could have several zones within them based on the physical layout of the building, or networking capacity, or because of incremental build out, or for any number of other reasons, none of which are relevant to a user.

	The term "zone" was adopted at a time when we weren't really focusing on mimicking the AWS Availability Zone concept, and in hindsight, it was a poor choice. So we should learn from that mistake and make sure we don't choose a replacement term that already has a common usage, such as shards segments or clusters.


-- Ed Leafe