TAP Notes

[Markus Demleitner]

Dear DAL list,

On Fri, Jan 03, 2014 at 09:19:06AM +0000, Paul Harrison wrote:
> 
> On 2013-12 -06, at 14:29, Markus Demleitner <msdemlei at ari.uni-heidelberg.de> wrote:
> To be honest Quote is something that I regret ever being included
> in UWS - it is difficult for a service to give a good quote and
> difficult for a client to take any action on any quote given
> (especially as it is optional). I would be tempted towards trying

Thank you for giving me the opportunity to make again my standard
point on the undesirability of optional features...

> to drop it in any future version, although changing to seconds
> would be more sensible and then the test of ?potential success?
> would be against the execution duration rather than the destruction
> time - see
> https://volute.googlecode.com/svn/trunk/projects/grid/uws/doc/UWS.html#Quote

I believe the rationale given there -- "a client creates the same job
on several services, compares the quotes and then accepts the best
quote" -- is a very valid use case as TAP usage increases and people
start running large jobs.  So, I'd like too keep the "give me a
handle on where my job will run the fastest" thing but make it
something that's computable with reasonable effort.

The only thing that comes to my mind would be "current queue length".
Without information on what those queued jobs are, that's admittedly
weak.  But it's simple enough and probably still a useful measure, so
*if* we agree on doing away with quote in UWS2, I'd like to submit it
as a candidate replacement.


Paul -- if you really think we should do away with quote, would you
write a section to that effect into the TAP notes so we can start a
discussion over at GWS?  I suspect there's going to be some
resistance.  Quote may be hard for TAP/ADQL, but it may be
straightforward for other UWS applications, and people may be using
quote there already.

Cheers,

        Markus