[occi-wg] Yet Another (non)Link Proposal

[Gary Mazz]

Good work, Andy's write up seems to capture many of our issues, from 
current linking discussions in [1].

I think we need to revisit the reasons why we have linking in the first 
place.

1) Initially we knew we weren't able to capture all aspects of cloud 
architectures and our preliminary work would need to be extensible. We 
needed a way to integrate changes into occi.
2) We also realized we would need to integrate vendor proprietary  
implementations.
3) Additionally, we decided that we need to breakup the occi represented 
resources into small parts for easy transport and support devices like 
mobile phones.

This was all  decided prior to the introduction of the occi http header 
implementation.

During this process, we decided to use linking, again prior to headers, 
to represent both References between resources and Associations between 
representations out of occi's scope.

This approach intuitively combined issues surrounding data context and 
data data description into an predetermined implementation as a 'link'. 
I think link we need to further define the term as 'Link' which refers 
to OCCI both type of occi associations and the 'link' for the 
implementation used in headers and HTML/RDFa.

*The Proposal:*

*Name Changes:*
I would prefer to see 'Link' to be renamed to "Reference' and 
'Association' where appropriate in the occi specification.  It would 
help limit confusion on the part of implementors and contributors. 

*New Definitions:*

*Reference: *A portion of the occi logical model representing an occi 
configuration indicating a binding relationship between occi entities.
**
*Association: *A portion of the occi logical model representing an occi 
configuration indicating a bind relationship between occi entities and 
systems outside the scope of occi.
**
*Logic Rules:
**Reference: *
*Rule 1: *All References are part of the occi name space.
*Rule 2: *One occi element is represented by one Reference.

* Association: *
*Rule 1: *Associations are used to extend occi  with system entities 
outside of occi's scope. Interoperability cannot be guaranteed across 
occi extensions.
*Rule 2: *Although indented for external systems, occi entities may be a 
defined in Associations. This would help ensure backward compatibility 
if an extension is adopted and becomes part of the occi name space. *
Rule 3:*  Detailed information about the occi extension is only 
available after the extension is loaded be the extension consumer.
*Rule 4:* The URI is mandatory for an Association.
*Rule 5:* An occi Title attribute is mandatory for an Association.
*Rule 6:* An occi Summary attribute is optional for an Association.


*Header Implementation Details:*
Remove the Link field from the header definition and replace it with the 
appropriate Reference  and  Association header field.

*Header Implementation Benefit:*
1) Reduces Link attribute parsing complexity
2) Reduces provides better clarity of the information's purpose
*
HTML5/RDFa Implementation Details:*
TBD

I'll follow up with examples if there is interest

cheers,
gary



[1] http://forge.ogf.org/sf/wiki/do/viewPage/projects.occi-wg/wiki/Link


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.ogf.org/pipermail/occi-wg/attachments/20100817/c19f797b/attachment.html