[occi-wg] Nouns and Verbs (was: Syntax of OCCI API) - state model

[Ignacio Martin Llorente]

My position is that if DMTF already provides a life-cycle model, we  
should adopt it as long as it meets the requirements from use cases.

Regards
--
Ignacio M. Llorente, Full Professor (Catedratico): web http://dsa-research.org/llorente 
  and blog http://imllorente.dsa-research.org/
DSA Research Group:  web http://dsa-research.org and blog http://blog.dsa-research.org
Globus GridWay Metascheduler: http://www.GridWay.org
OpenNebula Virtual Infrastructure Engine: http://www.OpenNebula.org









On 17/04/2009, at 16:21, Andre Merzky wrote:

> Quoting [Lars Larsson] (Apr 17 2009):
>>
>> On Fri, 17 Apr 2009, Ignacio Martin Llorente wrote:
>>
>>> We do not need "migrated", that is an internal operation that can  
>>> not
>>> be requested using a Cloud API
>>
>> I fully agree with Ignacio.
>>
>> I think there is a difference between the set of states that a
>> VM can be in, and the set of states that may be set using the
>> API. The first set may be larger and include informational
>> states such as "being migrated" or "being copied", but that does
>> not mean that the user can actively request that a VM should be
>> migrated.
>
> Yes, I agree with that: active versus informational states.
> Again, other state models in OGF represent such information
> as substates, e.g. 'Migrating' might be expressed as a
> substate of 'Running'.  I am not saying this is how this
> group should do state modeling, just for information...
>
>
>> I suggest that we use the states shown at page 25 in "CIM System
>> Virtualization White Paper" by the DMTF (DSP2013), available
>> here:
>>
>> 	http://www.dmtf.org/standards/published_documents/DSP2013_1.0.0.pdf
>
> That is an interesting model - it seems a lot of people have
> been thinking hard about that :-)   I like it...
>
> To play the devils advocate though:
>
>  - Is that state model suitable for our use cases?  It
>    seems to allow for quite a large number of transissions,
>    but is missing the 'Initial -> Suspended' transition
>    which has been discussed on this list earlier.
>
>  - The design seems to have been motivated by physical
>    states rather than logical states (the power state notes
>    are an artifact of that I guess?).  Are the states
>    applicable to our use cases?
>
>  - Do we need a distinction between 'VS State' and 'Enabled
>    State'?  The document says: " the EnabledState property
>    represents the virtual system’s state" - so, what is the
>    difference to VS state, which is, I take, also the
>    virtual system state?  The document does not offer a
>    better definition/distinction AFICS.
>
>
>> Displaying extra information, such as "being migrated" or "being
>> copied" is up to the infrastructure provider to optionally add
>> to the description of the state that is reported via monitoring.
>
> +1
>
> Best, Andre.
>
>
> -- 
> Nothing is ever easy.