[dotNetRDF-Support] stardog connector & handling of authentication credentials

[Mark D W. <mar...@ko...>]

Hello,

I noticed in doing some simple performance testing that executing a simple SPARQL query against a Stardog SPARQL endpoint via the Stardog connector versus using the SparqlConnector took considerably longer.

That is, executing

            using (StardogConnector stardog = new StardogConnector(stardogURL, SparqlDB, "admin", "admin"))
            {
                    // execute SPARQL query
            }

takes longer than:

            using (SparqlConnector sc = new SparqlConnector(new Uri(endptURL)))
            {
                sc.Endpoint.SetCredentials("admin", "admin");
               // do SPARQL query
            }

Watching the traffic with Fiddler, I see that with the Stardog connector, it first attempts to execute the query w/o specifying the authentication credentials, which results in a 401 error; it then reissues the query with the credentials.   So it takes longer, because of the retry.

Any reason why the credentials aren't passed the first time?

Thanks,

-Mark