UWS pattern makes scratch VOSpace redundant

[Matthew Graham]

Hi Paul,

This sounds very similar to the Cloudspace concept that I presented at 
ADASS two weeks ago. Cloudspace is an extension of VOSpace incorporating 
the UWS interface so that services and data objects are addressable 
within the same space. A mapping mechanism between URIs (think UNIX 
links) means that the results of a service can also be identified as a 
data object.

    Cheers,

    Matthew

Paul Harrison wrote:
> Hi,
>
> I have been thinking about one of the use cases that we been 
> advocating for VOSpace- that of using it for temporary storage of 
> results between steps in a workflow. This has been a principal use of 
> MySpace within Astrogrid for instance. The UWS pattern allows for each 
> service to be the  temporary storage for the data that is to be the 
> input to the next step in the workflow i.e. the second application can 
> read data from the (jobs)/(jobid)/results uri of the first step. This 
> is both easier to implement and more efficient in data transport terms 
> than moving the data into a scratch VOSpace. UWS provides all of the 
> data management facilities needed for this simple scenario.
>
> The above conclusion holds for a set of distributed UWS services an a 
> centralized VOSpace - if services are co-located then the conclusions 
> become more complex. Imagine that there is a UWS data processing 
> service and a co-located VOSpace service, where the two services 
> actually share the same backend storage - i.e. in VOSpace terms the 
> file: protocol could be used by the UWS to retrieve the data. In this 
> case there could be some benefit to having a co-located VOSpace 
> because  the data could be retrieved and put to the VOSpace very 
> efficiently and it allows for long term storage, so that the combined 
> UWS/VOSpace service could gradually accumulate raw and processed data 
> products that perhaps with the addition of a colocated Querying 
> service could provide a valuable dataset.
>
> Cheers,
>     Paul.
>
> .
> Dr. Paul Harrison
> JBCA, Manchester University
> http://www.manchester.ac.uk/jodrellbank
>
>
>