I think it's how the client is creating the request, since one client can send it and get a reply and another cannot send or not properly creating it such that low level programs cannot send the request, not sure though
On 24 Nov 2017 10:58, "Andy Seaborne" <[email protected]> wrote: > > > On 24/11/17 09:30, Mohammad Noorani Bakerally wrote: > >> Just checked something, I've used the SPARQL Client YASGUI and the sparql >> query is answered properly, can we deduce that the issue is with the >> client >> ? >> > > That would seem most likely, something on the network path from client to > server - it is so hard to be definite about these low level errors. > > Andy > > >> >> >> >> >> On Fri, Nov 24, 2017 at 10:22 AM, Mohammad Noorani Bakerally < >> [email protected]> wrote: >> >> Yes, I'm going to check the logs, but so far, a query like SELECT * WHERE >>> { ?s ?p ?o .} LIMIT 10 is properly handled and results is returned, I can >>> share the sparql endpoint, it is http://opensensingcity. >>> emse.fr/sparql/bistro, it's just for some testing purposes, so if I >>> understand, if a query is answered, Fuseki must be properly configured >>> with >>> apache, the resets happens immediately and there is no delay, i've not >>> checked the log but it seems the request doesn't even go to the server >>> >>> >>> >>> >>> On Fri, Nov 24, 2017 at 10:03 AM, Andy Seaborne <[email protected]> wrote: >>> >>> HttpException: -1 Unexpected error making the query: >>>>> java.net.SocketException: Connection reset >>>>> >>>> >>>> This is a problem at a low level in the networking stack (fake status >>>> code -1 from Jena also says it's not an HTTP error). The other end >>>> responded with a TCP RST (the connection reset bit) which is attempt to >>>> use >>>> a connection the other end thinks is closed or does not exist. >>>> >>>> There are many reasons that can cause this - some kind of network >>>> environmental issue between client and server. >>>> >>>> Having a reverse proxy (RP) in front of the Fuseki server is one >>>> possible >>>> cause e.g. when Fuseki isn't there but the reverse proxy is, there can >>>> be a >>>> rejection at the TCP level. Or the RP has rebooted reboot. >>>> >>>> There are many reasons (StackOverflow has many questions about this). >>>> >>>> Check the Fuseki server log - did the query even reach the server? >>>> Resets >>>> usually happen at the start (e.g after a long period of no use and the >>>> RP >>>> has timed the connection out (Fuseki, standalone, hasn't configured to >>>> Jetty to do this).. >>>> >>>> If it did reach the server, then some intermediate may have forcefully >>>> closed the connection. >>>> >>>> Andy >>>> >>>> >>>> On 23/11/17 22:38, Mohammad Noorani Bakerally wrote: >>>> >>>> I am getting an exception when executing the following a valid construct >>>>> query on Fuseki via jena. Any idea about this problem ? >>>>> >>>>> The query: >>>>> ============== >>>>> PREFIX dcat: <http://www.w3.org/ns/dcat#> >>>>> PREFIX data: <http://opensensingcity.emse.fr/LDPDesign/data/> >>>>> PREFIX skos: <http://www.w3.org/2004/02/skos/core#> >>>>> PREFIX : <http://opensensingcity.emse.fr/LDPDesignVocabulary/> >>>>> CONSTRUCT { < >>>>> https://bistrotdepays.opendatasoft.com/id/theme/Sport%2C%20Loisirs> ?p >>>>> ?o . >>>>> } WHERE { < >>>>> https://bistrotdepays.opendatasoft.com/id/theme/Sport%2C%20Loisirs> ?p >>>>> ?o . >>>>> } >>>>> >>>>> >>>>> >>>>> The exception: >>>>> ============ >>>>> HttpException: -1 Unexpected error making the query: >>>>> java.net.SocketException: Connection reset >>>>> >>>>> at org.apache.jena.sparql.engine.http.HttpQuery.rewrap(HttpQuer >>>>> y.java:374) >>>>> at org.apache.jena.sparql.engine.http.HttpQuery.execGet(HttpQue >>>>> ry.java:337) >>>>> at org.apache.jena.sparql.engine.http.HttpQuery.exec(HttpQuery. >>>>> java:288) >>>>> at >>>>> org.apache.jena.sparql.engine.http.QueryEngineHTTP.execConst >>>>> ructWorker(QueryEngineHTTP.java:465) >>>>> at >>>>> org.apache.jena.sparql.engine.http.QueryEngineHTTP.execModel >>>>> (QueryEngineHTTP.java:428) >>>>> at >>>>> org.apache.jena.sparql.engine.http.QueryEngineHTTP.execConst >>>>> ruct(QueryEngineHTTP.java:389) >>>>> at >>>>> org.apache.jena.sparql.engine.http.QueryEngineHTTP.execConst >>>>> ruct(QueryEngineHTTP.java:384) >>>>> at >>>>> loader.configuration.SPARQLDataSource.executeGraphQuery(SPAR >>>>> QLDataSource.java:43) >>>>> at genPLDPD.Evaluation.evalRM(Evaluation.java:136) >>>>> >>>>> >>>> >>> >>
