Re: Graph Store Protocol HTTP status for empty graphs

Hi,

yes the use case this time was discovering if the service is available.

But we've implemented a GSP endpoint ourselves (a GSP proxy really),
and my understanding of the spec was always that even an empty default
graph should return 200 OK.

But after re-reading the relevant text re. "graph content [...] does
not exist", I can see that it's not as clear cut as it should be, and
I get why Dydra would interpret it as 404 Not Found. Even though that
feels counter-intuitive to me.

I've opened an issue for SPARQL 1.2: https://github.com/w3c/sparql-12/issues/115

On Sat, Sep 5, 2020 at 11:52 AM james anderson <james@dydra.com> wrote:
>
> good morning;
>
> > On 2020-09-05, at 11:24:55, Andy Seaborne <andy@apache.org> wrote:
> >
> >
> >
> > On 04/09/2020 16:46, Martynas Jusevičius wrote:
> >> OK. Shouldn't there be tests for this? At least for #1?
> >
> > Would you like to contribute some tests?
> >
> >> On Fri, Sep 4, 2020 at 5:40 PM Gregory Williams <greg@evilfunhouse.com> wrote:
> >>>
> >>> On Sep 4, 2020, at 2:24 AM, Martynas Jusevičius <martynas@atomgraph.com> wrote:
> >>>>
> >>>> Hi,
> >>>>
> >>>> I'd like to clarify what the HTTP status should be for these cases:
> >>>> 1. GET default graph which is empty
> >>>> 2. GET named graph which is empty
> >>>>
> >>>> I've looked at the GSP test suite, but I don't think they are covered:
> >>>> https://www.w3.org/2009/sparql/docs/tests/data-sparql11/http-rdf-update/
> >>>>
> >>>> Jena Fuseki returns 200 OK for #1 which makes sense to me (as the
> >>>> default graph always exists in an RDF dataset), but we use another
> >>>> product which returns 404 Not Found.
> >
> > Better to discuss that with "the other product" to see what they say first.
>
> he did.
> he did not appreciate our interpretation.
> the initial objection being, because it is not what jena does.
>
> i suggested that, given his use case - to determine whether a sparql endpoint is available, it would be more portable to probe that endpoint for a service description.
> as that is a response which is well defined, that method should be preferred to probing a different service in the hope of eliciting some response which is not.
>
> best regards. from berlin,
> ---
> james anderson | james@dydra.com | http://dydra.com
>
>
>
>
>
>

Received on Saturday, 5 September 2020 10:00:00 UTC