UWS 1.1

[Patrick Dowler]

I have (crudely) implemented this and it should go live in a day or 
so... will announce it here when it is available.

One thing that came to mind while implementing this is that it is really 
quite complex if you have load-balanced web servers. As such, I ended up 
using internal polling in case events don't get propagated(*) from the 
server running the job to the server someone is blocking on... but I 
don't know how responsive the client wants. It seems it would be nice if 
the client could say "if I had to do it, I would poll every 300ms but 
I'm being nice and WAIT=30 (sec)"... The best solution is to have a 
distributed event mechanism on the server side but I can see that not 
having a great cost:benefit ratio. Maybe if the client could give a hint 
about responsiveness then server-side polling could be tuned 
sufficiently... WAIT=30&THREATEN-TO-POLL=100ms ? :-)

* meaning that right now I don't do this at all :-)

Pat


On 21/05/15 05:50 AM, Mark Taylor wrote:
> Hi grid,
>
> I'm interested in implementing a UWS-1.1-aware client in order to
> improve the way that I do blocking to wait for an asynchronous
> TAP response (sec 2.2.1.1).
>
> Are there some deployed TAP services out there that implement
> UWS-1.1 blocking behaviour?  Preferably using the UWS 1.1 namespace?
> I'd like to test client behaviour against them.
>
> Thanks
>
> Mark
>
> On Tue, 19 May 2015, Paul Harrison wrote:
>
>> Hi,
>>
>> We are hoping to advance UWS 1.1 to PR status at (or perhaps before) the Sesto Interop Meeting. I believe that there are now several implementations that are being updated to adhere to the new version. It has been brought to my attention that the UWS 1.1 schema was not available in the text of the last WD that was published to the IVOA document store. For those that need a copy, it is available in volute
>>
>> https://code.google.com/p/volute/source/browse/trunk/projects/grid/uws/doc/UWS.xsd
>>
>> In addition I have made some small edits to the standard document - in preparation for PR - again this version is as yet only available in volute
>>
>> http://volute.googlecode.com/svn/trunk/projects/grid/uws/doc/UWS.html
>>
>> I believe that there is only one outstanding issue in this document in section 2.2.1.1 (http://volute.googlecode.com/svn/trunk/projects/grid/uws/doc/UWS.html#blocking) highlighted in yellow. It concerns how other standards might signal which version of UWS that they are using. My current feeling is to remove this text entirely and leave it up to the other standard documents to signal the mechanism that they want to use. I think that part of the cause for this versioning issue to come up was the lack of clarity of the namespace for the UWS schema - which is now addressed by the release of a schema with a new 1.1 namespace - therefore it is safe to remove this issue from the UWS specification. Any objections?
>>
>> As has recently been mentioned on the lists, we hope to have a session in Sesto on the topic of versioning of schema to form some guidelines for good practice.	
>>
>>
>> Regards,
>> 	Paul.
>>
>>
>>
>>
>
> --
> Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
> m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/
>

-- 

Patrick Dowler
Canadian Astronomy Data Centre
National Research Council Canada
5071 West Saanich Road
Victoria, BC V9E 2E7

250-363-0044 (office) 250-363-0045 (fax)