new version of REST in the VO

[Douglas Tody]

On Tue, 28 Oct 2008, Paul Harrison wrote:

> On 2008-10 -28, at 04:44, Douglas Tody wrote:
>
>> I think it is fine to define some recommended practices for interfaces
>> based upon the pure-REST abstraction, but this should not in any way
>> invalidate the DAL2 interface pattern(*), which is already standardized
>> and widely used within the VO (and also based upon a HTTP transport).
>
> point of order - the DAL v2 interface pattern is *not* already standardised, 
> we are in the process of trying to create a V2 protocol family that is more 
> capable/scalable than the v1 interface pattern - this is why GWS WG is 
> looking at using more advanced techniques than were employed in the v1 
> protocols.

It is true that the recent DAL2 architecture document per se is not a
standard, however essentially all the content therein was discussed
within the DAL WG for several years, leading up to promoting SSA
(the first of the second generation DAL interfaces, all of which
were intended to be consistent in terms of interface) to a standard.
SSA, and the older DAL interfaces which follow a similar pattern,
are VO standards in wide use within the community.

Note that there is no reason that interfaces such as DAL2 (which
is based upon OpenGIS standards) and facilities such as UWS (which
exemplifies the pure-REST approach) cannot coexist.  This is already
being demonstrated in TAP, and the same pattern can carry over
to future interfaces such as SIAV2.  This, plus eventual VOSpace
integration will provide the scalability we all want.

 	- Doug