Open Stack

On 04/25/2013 11:15 AM, John Griffith wrote:
> Hey Folks,
> 
> With the growth of vendor activity in the form of driver submissions in
> Cinder there's some concerns and challenges that I have and I'd like to
> get some thoughts from the TC as I move forward.
> 
> The short version here is:
>     "What is our goal with OpenStack WRT API behavior and implementation?"
> 
> 
> 
> The longer detailed version:
> 
> With the increased activity from Vendors in Cinder adding their drivers
> there's some conflicts regarding  what should be required for
> acceptance.  My position on this has been pretty simple (albeit
> unpopular) that if it's supported by the reference implementation (LVM
> Driver) and it's a core API call then those are your requirements.
> 
> In addition I feel that behaviors of the API should be standard
> regardless of what driver is being used.  For example; a number of folks
> have proposed that they should be able to do things like "delete a
> parent volume of a snapshot" if the driver supports it, if the driver
> doesn't then just return an error. 
> 
> My response to this has been NO WAY, because the result is different
> behaviors and expectations based on what driver is currently in use.

I agree with you 100% on this.

>  This is very bad IMO because the whole point of Cinder from my
> perspective is to abstract those differences and details out.  Adding
> functionality and features on top of the reference implementation (via
> extensions, types etc) is one thing, but deviating from the behavior is
> a very bad idea IMO.  It would be one thing if there was no way to
> achieve what the vendor would like to accomplish but the fact is in
> almost every one of these cases that comes up there's a way to do what
> they would like, it just doesn't use the vocabulary or semantics that
> they would like.
> 
> Anyway, I know we pushed the "what is OpenStack" back to the board at
> one point and I don't recall ever seeing a clear response on that.  What
> I'd like to do as a TC function is to actually define some sort of goal
> or mission statement of what we are hoping to provide.  This doesn't
> have to be a huge debate or a 1000 page manifesto, just a clear mission
> statement on what an end user or provider should expect when they
> install OpenStack projects and use the API.

Actually, the important response here is that it's on the TC to define
the technical characteristics. I believe your questions above are well
within scope.

I'll say this - the current stated value proposition for OpenStack is
that multiple inter-operable clouds that run OpenStack provide value for
the user by preventing vendor lock in.

We have several programs running right now to work on doing
interoperability definitions and testing.

I think that it's safe to say that the emerging view point is that the
user experience of using an OpenStack cloud should not be altered based
on implementation choices. To that end, I believe you've been making the
right call, and we need to continue pushing viewpoints such as that.

> I can continue to make my own calls on this which is fine with me, but I
> suspect that other projects either are dealing with, or will be dealing
> with this same sort of issue.  It might be worth discussing and putting
> some sort of concept around what our goal is here..

I'd be in favor of making a more formal technical statement around what
we think interoperability and API policy should look like here. You're
WELL within your rights as PTL to just be making that call right now -
but writing something down and being clear about it so that it doesn't
keep coming up might be friendly to people.