[TAP] sync vs async

[Roy Williams]

Patrick Dowler wrote:
> In cases where it works, sync is easier for the client, but I think we  agree 
> that it cannot be made robust in the general case. Async handles the general 
> case; this is why async is required. For the small extra work and utility, it 
> was deemed it simpler for everyone if sync was also required (plus the oddity 
> about VOSI requests noted above).
>   

Building the asynchronous versions of all these protocols is a large 
barrier to implementation of VO protocols, it is not "small extra work". 
Over and above the business logic of the sync service, there will have 
to be databases of customers and their running jobs, a security 
infrastructure so that one person cannot see/kill the job of another, a 
large filespace for storing intermediate results, reaper processes to 
clean out that space, and other complexities.

But why Oh Why must this complexity be mandatory? The DAL group is 
saying (on behalf of the IVOA) that the simple and useful synchonous 
service is Not Wanted as part of VO. Only large data centers are allowed 
to publish data the VO way. (In the real world, by contrast, the 
internet has reduced barriers to publication).

Imagine if we were making automobiles in 1900, trying to sell horseless 
carriages to skeptical public who already own horses. Now an 
over-zealous regulatory agent says that airbags and pollution controls 
and insurance are "mandatory". What a way to kill off the new industry!

Once again I plead with the IVOA, to try to keep it simple!

Roy

-- 

California Institute of Technology
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