Menu
▾
▴
dotnetrdf-support
|
From: Frank S. <fs...@in...> - 2014-03-18 13:12:39
|
Hi folks,
I am using the dotNetRDF-Framework to access a SPARQL-endpoint of our
virtuoso server. At first, let me thank you to provide this framework,
as it is a good tool for a semantic web beginner to get started with!
I just stumbled upon a mysterious error, which I hope you can shed some
light on. I am trying some examples to see how to insert/delete triples
to the graph. After executing a delete and an insert, the endpoint
doesn't react anymore and I run into a timeout. But let me show you some
code!
// define the endpoint
SparqlRemoteEndpoint endpoint = new SparqlRemoteEndpoint(new
Uri("http://www.creativeartefact.org/sparql"),
"http://139.18.2.148/MusicBusinessOntology");
endpoint.Timeout = 100000;
// get everything in the graph
string everything = "select * where {?s ?p ?o}";
// insert data
string insert1 = "INSERT DATA { GRAPH
<http://139.18.2.148/MusicBusinessOntology> {
<http://139.18.2.148/MusicBusinessOntology/URIDISILLU>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://artefakt.org/MusicBusinessVocabulary/MusicArtist>.
<http://139.18.2.148/MusicBusinessOntology/URIDISILLU>
<http://www.w3.org/2000/01/rdf-schema#label> \"Disillusion\" . } }";
// delete data
string delete1 = "DELETE WHERE { GRAPH
<http://139.18.2.148/MusicBusinessOntology> {
<http://139.18.2.148/MusicBusinessOntology/URIDISILLU> ?p ?o } }";
1) endpoint.QueryRaw(delete1);
2) endpoint.QueryRaw(insert1);
3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
when I execute delete and insert, the next query will run into a timeout
1) endpoint.QueryRaw(delete1);
3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
works
2) endpoint.QueryRaw(insert1);
3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
works as well
It is always the third request:
1) endpoint.QueryRaw(delete1);
2) endpoint.QueryRaw(insert1);
3) endpoint.QueryRaw(delete1);
4) endpoint.QueryRaw(insert1);
5) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
=> the timeout occurs at the third query.
I even put a breakpoint at the third line. Before executing this line, I
execute the select statement vie webinterface against the
SPAQRL-endpoint. The webinterface request works fine - but if I let the
program continue, it still runs into a timeout. I even tried a second
SparqlRemoteEndpoint instance - same problem.
Any idea, what might be the reason for this behaviour and how to fix it?
Many thanks,
Frank
--
************************************************
* Universität Leipzig, Institut für Informatik *
* Abteilung Betriebliche Informationssysteme *
* http://bis.informatik.uni-leipzig.de *
* Tel.: 0341 / 97 32 256 *
* *
* ========== Opera Metal: molllust =========== *
* http://www.molllust.com *
* M'era Luna Newcomer 2013! *
************************************************
|
|
From: Rob V. <rv...@do...> - 2014-03-18 14:18:22
|
I'm guessing you do anything with the result of the QueryRaw() call which
is a HttpWebResponse?
If you don't then you are leaving the connections open and the .Net
runtime imposes a limit on the number of open connections to a single
server. I believe this is in fact 2 connections hence why the third
request always fails since it is waiting for a connection to be free but
they are already used by the previous request. You should make sure you
wrap any usage of QueryRaw() in a using block like so:
using (HttpWebResponse response = endpoint.QueryRaw(update)) {
// If you get here then the request succeeded and we close the response
explicitly
response.Close();
}
Then even if the request errors the using block ensures that any response
gets disposed of (which internally closes the connection) so you are
covered either way.
You may want to consider using the complementary
SparqlRemoteUpdateEndpoint class for running updates, it has an Update()
method which handles submitting SPARQL updates and ensuring connections
are appropriately closed.
Hope this helps,
Rob
On 18/03/2014 13:12, "Frank Schumacher" <fs...@in...>
wrote:
>Hi folks,
>
>I am using the dotNetRDF-Framework to access a SPARQL-endpoint of our
>virtuoso server. At first, let me thank you to provide this framework,
>as it is a good tool for a semantic web beginner to get started with!
>
>I just stumbled upon a mysterious error, which I hope you can shed some
>light on. I am trying some examples to see how to insert/delete triples
>to the graph. After executing a delete and an insert, the endpoint
>doesn't react anymore and I run into a timeout. But let me show you some
>code!
>
>// define the endpoint
>SparqlRemoteEndpoint endpoint = new SparqlRemoteEndpoint(new
>Uri("http://www.creativeartefact.org/sparql"),
>"http://139.18.2.148/MusicBusinessOntology");
>endpoint.Timeout = 100000;
>
>// get everything in the graph
>string everything = "select * where {?s ?p ?o}";
>
>// insert data
>string insert1 = "INSERT DATA { GRAPH
><http://139.18.2.148/MusicBusinessOntology> {
><http://139.18.2.148/MusicBusinessOntology/URIDISILLU>
><http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
><http://artefakt.org/MusicBusinessVocabulary/MusicArtist>.
><http://139.18.2.148/MusicBusinessOntology/URIDISILLU>
><http://www.w3.org/2000/01/rdf-schema#label> \"Disillusion\" . } }";
>
>// delete data
>string delete1 = "DELETE WHERE { GRAPH
><http://139.18.2.148/MusicBusinessOntology> {
><http://139.18.2.148/MusicBusinessOntology/URIDISILLU> ?p ?o } }";
>
>1) endpoint.QueryRaw(delete1);
>2) endpoint.QueryRaw(insert1);
>3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>
>when I execute delete and insert, the next query will run into a timeout
>
>1) endpoint.QueryRaw(delete1);
>3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>works
>
>2) endpoint.QueryRaw(insert1);
>3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>works as well
>
>It is always the third request:
>1) endpoint.QueryRaw(delete1);
>2) endpoint.QueryRaw(insert1);
>3) endpoint.QueryRaw(delete1);
>4) endpoint.QueryRaw(insert1);
>5) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>
>=> the timeout occurs at the third query.
>
>I even put a breakpoint at the third line. Before executing this line, I
>execute the select statement vie webinterface against the
>SPAQRL-endpoint. The webinterface request works fine - but if I let the
>program continue, it still runs into a timeout. I even tried a second
>SparqlRemoteEndpoint instance - same problem.
>
>Any idea, what might be the reason for this behaviour and how to fix it?
>
>Many thanks,
>Frank
>
>--
>************************************************
>* Universität Leipzig, Institut für Informatik *
>* Abteilung Betriebliche Informationssysteme *
>* http://bis.informatik.uni-leipzig.de *
>* Tel.: 0341 / 97 32 256 *
>* *
>* ========== Opera Metal: molllust =========== *
>* http://www.molllust.com *
>* M'era Luna Newcomer 2013! *
>************************************************
>
>--------------------------------------------------------------------------
>----
>Learn Graph Databases - Download FREE O'Reilly Book
>"Graph Databases" is the definitive new guide to graph databases and their
>applications. Written by three acclaimed leaders in the field,
>this first edition is now available. Download your free book today!
>http://p.sf.net/sfu/13534_NeoTech
>_______________________________________________
>dotNetRDF-Support mailing list
>dot...@li...
>https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support
|
|
From: Frank S. <fs...@in...> - 2014-03-18 15:13:13
|
Hey Rob,
this was exactly the problem! Thanks a lot!
I also considered your recomendation about using the
SparqlRemoteUpdateEndpoint class - it works fine. Is it possible to get
any feedback about the success of the action like in sql (from where I
come), i.e. "5 triples deleted" or "2 triples inserted"?
Thanks again, you saved my day :)
Frank
Am 18.03.2014 15:17, schrieb Rob Vesse:
> I'm guessing you do anything with the result of the QueryRaw() call which
> is a HttpWebResponse?
>
> If you don't then you are leaving the connections open and the .Net
> runtime imposes a limit on the number of open connections to a single
> server. I believe this is in fact 2 connections hence why the third
> request always fails since it is waiting for a connection to be free but
> they are already used by the previous request. You should make sure you
> wrap any usage of QueryRaw() in a using block like so:
>
> using (HttpWebResponse response = endpoint.QueryRaw(update)) {
> // If you get here then the request succeeded and we close the response
> explicitly
> response.Close();
> }
>
> Then even if the request errors the using block ensures that any response
> gets disposed of (which internally closes the connection) so you are
> covered either way.
>
> You may want to consider using the complementary
> SparqlRemoteUpdateEndpoint class for running updates, it has an Update()
> method which handles submitting SPARQL updates and ensuring connections
> are appropriately closed.
>
> Hope this helps,
>
> Rob
>
> On 18/03/2014 13:12, "Frank Schumacher" <fs...@in...>
> wrote:
>
>> Hi folks,
>>
>> I am using the dotNetRDF-Framework to access a SPARQL-endpoint of our
>> virtuoso server. At first, let me thank you to provide this framework,
>> as it is a good tool for a semantic web beginner to get started with!
>>
>> I just stumbled upon a mysterious error, which I hope you can shed some
>> light on. I am trying some examples to see how to insert/delete triples
>> to the graph. After executing a delete and an insert, the endpoint
>> doesn't react anymore and I run into a timeout. But let me show you some
>> code!
>>
>> // define the endpoint
>> SparqlRemoteEndpoint endpoint = new SparqlRemoteEndpoint(new
>> Uri("http://www.creativeartefact.org/sparql"),
>> "http://139.18.2.148/MusicBusinessOntology");
>> endpoint.Timeout = 100000;
>>
>> // get everything in the graph
>> string everything = "select * where {?s ?p ?o}";
>>
>> // insert data
>> string insert1 = "INSERT DATA { GRAPH
>> <http://139.18.2.148/MusicBusinessOntology> {
>> <http://139.18.2.148/MusicBusinessOntology/URIDISILLU>
>> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
>> <http://artefakt.org/MusicBusinessVocabulary/MusicArtist>.
>> <http://139.18.2.148/MusicBusinessOntology/URIDISILLU>
>> <http://www.w3.org/2000/01/rdf-schema#label> \"Disillusion\" . } }";
>>
>> // delete data
>> string delete1 = "DELETE WHERE { GRAPH
>> <http://139.18.2.148/MusicBusinessOntology> {
>> <http://139.18.2.148/MusicBusinessOntology/URIDISILLU> ?p ?o } }";
>>
>> 1) endpoint.QueryRaw(delete1);
>> 2) endpoint.QueryRaw(insert1);
>> 3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>>
>> when I execute delete and insert, the next query will run into a timeout
>>
>> 1) endpoint.QueryRaw(delete1);
>> 3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>> works
>>
>> 2) endpoint.QueryRaw(insert1);
>> 3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>> works as well
>>
>> It is always the third request:
>> 1) endpoint.QueryRaw(delete1);
>> 2) endpoint.QueryRaw(insert1);
>> 3) endpoint.QueryRaw(delete1);
>> 4) endpoint.QueryRaw(insert1);
>> 5) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>>
>> => the timeout occurs at the third query.
>>
>> I even put a breakpoint at the third line. Before executing this line, I
>> execute the select statement vie webinterface against the
>> SPAQRL-endpoint. The webinterface request works fine - but if I let the
>> program continue, it still runs into a timeout. I even tried a second
>> SparqlRemoteEndpoint instance - same problem.
>>
>> Any idea, what might be the reason for this behaviour and how to fix it?
>>
>> Many thanks,
>> Frank
>>
>> --
>> ************************************************
>> * Universität Leipzig, Institut für Informatik *
>> * Abteilung Betriebliche Informationssysteme *
>> * http://bis.informatik.uni-leipzig.de *
>> * Tel.: 0341 / 97 32 256 *
>> * *
>> * ========== Opera Metal: molllust =========== *
>> * http://www.molllust.com *
>> * M'era Luna Newcomer 2013! *
>> ************************************************
>>
>> --------------------------------------------------------------------------
>> ----
>> Learn Graph Databases - Download FREE O'Reilly Book
>> "Graph Databases" is the definitive new guide to graph databases and their
>> applications. Written by three acclaimed leaders in the field,
>> this first edition is now available. Download your free book today!
>> http://p.sf.net/sfu/13534_NeoTech
>> _______________________________________________
>> dotNetRDF-Support mailing list
>> dot...@li...
>> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support
>
>
>
>
>
> ------------------------------------------------------------------------------
> Learn Graph Databases - Download FREE O'Reilly Book
> "Graph Databases" is the definitive new guide to graph databases and their
> applications. Written by three acclaimed leaders in the field,
> this first edition is now available. Download your free book today!
> http://p.sf.net/sfu/13534_NeoTech
> _______________________________________________
> dotNetRDF-Support mailing list
> dot...@li...
> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support
>
--
************************************************
* Universität Leipzig, Institut für Informatik *
* Abteilung Betriebliche Informationssysteme *
* http://bis.informatik.uni-leipzig.de *
* Tel.: 0341 / 97 32 256 *
* *
* ========== Opera Metal: molllust =========== *
* http://www.molllust.com *
* M'era Luna Newcomer 2013! *
************************************************
|
|
From: Rob V. <rv...@do...> - 2014-03-18 15:19:43
|
Frank
Unfortunately that information is not available in most (if not all) cases.
The SPARQL specifications don't require implementations to track how many
triples were inserted/deleted so there is no standard for responding with
this information over HTTP. You mentioned you are using Virtuoso who are
well known for their non-standard SPARQL extensions so it may be worth
searching their documentation to see if they actually return this
information over HTTP in any way.
Or a quicker way may be to try an update through your browser and use a
browser extension to view the HTTP headers of the response to see if they
include that information in a custom header.
Rob
On 18/03/2014 15:12, "Frank Schumacher" <fs...@in...>
wrote:
>Hey Rob,
>
>this was exactly the problem! Thanks a lot!
>I also considered your recomendation about using the
>SparqlRemoteUpdateEndpoint class - it works fine. Is it possible to get
>any feedback about the success of the action like in sql (from where I
>come), i.e. "5 triples deleted" or "2 triples inserted"?
>
>Thanks again, you saved my day :)
>Frank
>
>Am 18.03.2014 15:17, schrieb Rob Vesse:
>> I'm guessing you do anything with the result of the QueryRaw() call
>>which
>> is a HttpWebResponse?
>>
>> If you don't then you are leaving the connections open and the .Net
>> runtime imposes a limit on the number of open connections to a single
>> server. I believe this is in fact 2 connections hence why the third
>> request always fails since it is waiting for a connection to be free but
>> they are already used by the previous request. You should make sure you
>> wrap any usage of QueryRaw() in a using block like so:
>>
>> using (HttpWebResponse response = endpoint.QueryRaw(update)) {
>> // If you get here then the request succeeded and we close the
>>response
>> explicitly
>> response.Close();
>> }
>>
>> Then even if the request errors the using block ensures that any
>>response
>> gets disposed of (which internally closes the connection) so you are
>> covered either way.
>>
>> You may want to consider using the complementary
>> SparqlRemoteUpdateEndpoint class for running updates, it has an Update()
>> method which handles submitting SPARQL updates and ensuring connections
>> are appropriately closed.
>>
>> Hope this helps,
>>
>> Rob
>>
>> On 18/03/2014 13:12, "Frank Schumacher" <fs...@in...>
>> wrote:
>>
>>> Hi folks,
>>>
>>> I am using the dotNetRDF-Framework to access a SPARQL-endpoint of our
>>> virtuoso server. At first, let me thank you to provide this framework,
>>> as it is a good tool for a semantic web beginner to get started with!
>>>
>>> I just stumbled upon a mysterious error, which I hope you can shed some
>>> light on. I am trying some examples to see how to insert/delete triples
>>> to the graph. After executing a delete and an insert, the endpoint
>>> doesn't react anymore and I run into a timeout. But let me show you
>>>some
>>> code!
>>>
>>> // define the endpoint
>>> SparqlRemoteEndpoint endpoint = new SparqlRemoteEndpoint(new
>>> Uri("http://www.creativeartefact.org/sparql"),
>>> "http://139.18.2.148/MusicBusinessOntology");
>>> endpoint.Timeout = 100000;
>>>
>>> // get everything in the graph
>>> string everything = "select * where {?s ?p ?o}";
>>>
>>> // insert data
>>> string insert1 = "INSERT DATA { GRAPH
>>> <http://139.18.2.148/MusicBusinessOntology> {
>>> <http://139.18.2.148/MusicBusinessOntology/URIDISILLU>
>>> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
>>> <http://artefakt.org/MusicBusinessVocabulary/MusicArtist>.
>>> <http://139.18.2.148/MusicBusinessOntology/URIDISILLU>
>>> <http://www.w3.org/2000/01/rdf-schema#label> \"Disillusion\" . } }";
>>>
>>> // delete data
>>> string delete1 = "DELETE WHERE { GRAPH
>>> <http://139.18.2.148/MusicBusinessOntology> {
>>> <http://139.18.2.148/MusicBusinessOntology/URIDISILLU> ?p ?o } }";
>>>
>>> 1) endpoint.QueryRaw(delete1);
>>> 2) endpoint.QueryRaw(insert1);
>>> 3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>>>
>>> when I execute delete and insert, the next query will run into a
>>>timeout
>>>
>>> 1) endpoint.QueryRaw(delete1);
>>> 3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>>> works
>>>
>>> 2) endpoint.QueryRaw(insert1);
>>> 3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>>> works as well
>>>
>>> It is always the third request:
>>> 1) endpoint.QueryRaw(delete1);
>>> 2) endpoint.QueryRaw(insert1);
>>> 3) endpoint.QueryRaw(delete1);
>>> 4) endpoint.QueryRaw(insert1);
>>> 5) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>>>
>>> => the timeout occurs at the third query.
>>>
>>> I even put a breakpoint at the third line. Before executing this line,
>>>I
>>> execute the select statement vie webinterface against the
>>> SPAQRL-endpoint. The webinterface request works fine - but if I let the
>>> program continue, it still runs into a timeout. I even tried a second
>>> SparqlRemoteEndpoint instance - same problem.
>>>
>>> Any idea, what might be the reason for this behaviour and how to fix
>>>it?
>>>
>>> Many thanks,
>>> Frank
>>>
>>> --
>>> ************************************************
>>> * Universität Leipzig, Institut für Informatik *
>>> * Abteilung Betriebliche Informationssysteme *
>>> * http://bis.informatik.uni-leipzig.de *
>>> * Tel.: 0341 / 97 32 256 *
>>> * *
>>> * ========== Opera Metal: molllust =========== *
>>> * http://www.molllust.com *
>>> * M'era Luna Newcomer 2013! *
>>> ************************************************
>>>
>>>
>>>------------------------------------------------------------------------
>>>--
>>> ----
>>> Learn Graph Databases - Download FREE O'Reilly Book
>>> "Graph Databases" is the definitive new guide to graph databases and
>>>their
>>> applications. Written by three acclaimed leaders in the field,
>>> this first edition is now available. Download your free book today!
>>> http://p.sf.net/sfu/13534_NeoTech
>>> _______________________________________________
>>> dotNetRDF-Support mailing list
>>> dot...@li...
>>> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support
>>
>>
>>
>>
>>
>>
>>-------------------------------------------------------------------------
>>-----
>> Learn Graph Databases - Download FREE O'Reilly Book
>> "Graph Databases" is the definitive new guide to graph databases and
>>their
>> applications. Written by three acclaimed leaders in the field,
>> this first edition is now available. Download your free book today!
>> http://p.sf.net/sfu/13534_NeoTech
>> _______________________________________________
>> dotNetRDF-Support mailing list
>> dot...@li...
>> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support
>>
>
>
>--
>************************************************
>* Universität Leipzig, Institut für Informatik *
>* Abteilung Betriebliche Informationssysteme *
>* http://bis.informatik.uni-leipzig.de *
>* Tel.: 0341 / 97 32 256 *
>* *
>* ========== Opera Metal: molllust =========== *
>* http://www.molllust.com *
>* M'era Luna Newcomer 2013! *
>************************************************
>
>--------------------------------------------------------------------------
>----
>Learn Graph Databases - Download FREE O'Reilly Book
>"Graph Databases" is the definitive new guide to graph databases and their
>applications. Written by three acclaimed leaders in the field,
>this first edition is now available. Download your free book today!
>http://p.sf.net/sfu/13534_NeoTech
>_______________________________________________
>dotNetRDF-Support mailing list
>dot...@li...
>https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support
|
|
From: Frank S. <fs...@in...> - 2014-03-18 15:54:45
|
Hey Rob,
ah, ok. I did not know this. As I am a big fan of using standards and my
SPARQL-queries should work with more than a virtuoso endpoint, I would
go with the specification and don't expect non-standard feedback.
At least I can wrap the call in a try/catch block to get any errors from
the server. If none is thrown, I'd asume my operation finished as intended.
Thanks again,
Frank
Am 18.03.2014 16:18, schrieb Rob Vesse:
> Frank
>
> Unfortunately that information is not available in most (if not all) cases.
>
> The SPARQL specifications don't require implementations to track how many
> triples were inserted/deleted so there is no standard for responding with
> this information over HTTP. You mentioned you are using Virtuoso who are
> well known for their non-standard SPARQL extensions so it may be worth
> searching their documentation to see if they actually return this
> information over HTTP in any way.
>
> Or a quicker way may be to try an update through your browser and use a
> browser extension to view the HTTP headers of the response to see if they
> include that information in a custom header.
>
> Rob
>
> On 18/03/2014 15:12, "Frank Schumacher" <fs...@in...>
> wrote:
>
>> Hey Rob,
>>
>> this was exactly the problem! Thanks a lot!
>> I also considered your recomendation about using the
>> SparqlRemoteUpdateEndpoint class - it works fine. Is it possible to get
>> any feedback about the success of the action like in sql (from where I
>> come), i.e. "5 triples deleted" or "2 triples inserted"?
>>
>> Thanks again, you saved my day :)
>> Frank
>>
>> Am 18.03.2014 15:17, schrieb Rob Vesse:
>>> I'm guessing you do anything with the result of the QueryRaw() call
>>> which
>>> is a HttpWebResponse?
>>>
>>> If you don't then you are leaving the connections open and the .Net
>>> runtime imposes a limit on the number of open connections to a single
>>> server. I believe this is in fact 2 connections hence why the third
>>> request always fails since it is waiting for a connection to be free but
>>> they are already used by the previous request. You should make sure you
>>> wrap any usage of QueryRaw() in a using block like so:
>>>
>>> using (HttpWebResponse response = endpoint.QueryRaw(update)) {
>>> // If you get here then the request succeeded and we close the
>>> response
>>> explicitly
>>> response.Close();
>>> }
>>>
>>> Then even if the request errors the using block ensures that any
>>> response
>>> gets disposed of (which internally closes the connection) so you are
>>> covered either way.
>>>
>>> You may want to consider using the complementary
>>> SparqlRemoteUpdateEndpoint class for running updates, it has an Update()
>>> method which handles submitting SPARQL updates and ensuring connections
>>> are appropriately closed.
>>>
>>> Hope this helps,
>>>
>>> Rob
>>>
>>> On 18/03/2014 13:12, "Frank Schumacher" <fs...@in...>
>>> wrote:
>>>
>>>> Hi folks,
>>>>
>>>> I am using the dotNetRDF-Framework to access a SPARQL-endpoint of our
>>>> virtuoso server. At first, let me thank you to provide this framework,
>>>> as it is a good tool for a semantic web beginner to get started with!
>>>>
>>>> I just stumbled upon a mysterious error, which I hope you can shed some
>>>> light on. I am trying some examples to see how to insert/delete triples
>>>> to the graph. After executing a delete and an insert, the endpoint
>>>> doesn't react anymore and I run into a timeout. But let me show you
>>>> some
>>>> code!
>>>>
>>>> // define the endpoint
>>>> SparqlRemoteEndpoint endpoint = new SparqlRemoteEndpoint(new
>>>> Uri("http://www.creativeartefact.org/sparql"),
>>>> "http://139.18.2.148/MusicBusinessOntology");
>>>> endpoint.Timeout = 100000;
>>>>
>>>> // get everything in the graph
>>>> string everything = "select * where {?s ?p ?o}";
>>>>
>>>> // insert data
>>>> string insert1 = "INSERT DATA { GRAPH
>>>> <http://139.18.2.148/MusicBusinessOntology> {
>>>> <http://139.18.2.148/MusicBusinessOntology/URIDISILLU>
>>>> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
>>>> <http://artefakt.org/MusicBusinessVocabulary/MusicArtist>.
>>>> <http://139.18.2.148/MusicBusinessOntology/URIDISILLU>
>>>> <http://www.w3.org/2000/01/rdf-schema#label> \"Disillusion\" . } }";
>>>>
>>>> // delete data
>>>> string delete1 = "DELETE WHERE { GRAPH
>>>> <http://139.18.2.148/MusicBusinessOntology> {
>>>> <http://139.18.2.148/MusicBusinessOntology/URIDISILLU> ?p ?o } }";
>>>>
>>>> 1) endpoint.QueryRaw(delete1);
>>>> 2) endpoint.QueryRaw(insert1);
>>>> 3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>>>>
>>>> when I execute delete and insert, the next query will run into a
>>>> timeout
>>>>
>>>> 1) endpoint.QueryRaw(delete1);
>>>> 3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>>>> works
>>>>
>>>> 2) endpoint.QueryRaw(insert1);
>>>> 3) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>>>> works as well
>>>>
>>>> It is always the third request:
>>>> 1) endpoint.QueryRaw(delete1);
>>>> 2) endpoint.QueryRaw(insert1);
>>>> 3) endpoint.QueryRaw(delete1);
>>>> 4) endpoint.QueryRaw(insert1);
>>>> 5) SparqlResultSet results = endpoint.QueryWithResultSet(everything);
>>>>
>>>> => the timeout occurs at the third query.
>>>>
>>>> I even put a breakpoint at the third line. Before executing this line,
>>>> I
>>>> execute the select statement vie webinterface against the
>>>> SPAQRL-endpoint. The webinterface request works fine - but if I let the
>>>> program continue, it still runs into a timeout. I even tried a second
>>>> SparqlRemoteEndpoint instance - same problem.
>>>>
>>>> Any idea, what might be the reason for this behaviour and how to fix
>>>> it?
>>>>
>>>> Many thanks,
>>>> Frank
>>>>
>>>> --
>>>> ************************************************
>>>> * Universität Leipzig, Institut für Informatik *
>>>> * Abteilung Betriebliche Informationssysteme *
>>>> * http://bis.informatik.uni-leipzig.de *
>>>> * Tel.: 0341 / 97 32 256 *
>>>> * *
>>>> * ========== Opera Metal: molllust =========== *
>>>> * http://www.molllust.com *
>>>> * M'era Luna Newcomer 2013! *
>>>> ************************************************
>>>>
>>>>
>>>> ------------------------------------------------------------------------
>>>> --
>>>> ----
>>>> Learn Graph Databases - Download FREE O'Reilly Book
>>>> "Graph Databases" is the definitive new guide to graph databases and
>>>> their
>>>> applications. Written by three acclaimed leaders in the field,
>>>> this first edition is now available. Download your free book today!
>>>> http://p.sf.net/sfu/13534_NeoTech
>>>> _______________________________________________
>>>> dotNetRDF-Support mailing list
>>>> dot...@li...
>>>> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support
>>>
>>>
>>>
>>>
>>>
>>>
>>> -------------------------------------------------------------------------
>>> -----
>>> Learn Graph Databases - Download FREE O'Reilly Book
>>> "Graph Databases" is the definitive new guide to graph databases and
>>> their
>>> applications. Written by three acclaimed leaders in the field,
>>> this first edition is now available. Download your free book today!
>>> http://p.sf.net/sfu/13534_NeoTech
>>> _______________________________________________
>>> dotNetRDF-Support mailing list
>>> dot...@li...
>>> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support
>>>
>>
>>
>> --
>> ************************************************
>> * Universität Leipzig, Institut für Informatik *
>> * Abteilung Betriebliche Informationssysteme *
>> * http://bis.informatik.uni-leipzig.de *
>> * Tel.: 0341 / 97 32 256 *
>> * *
>> * ========== Opera Metal: molllust =========== *
>> * http://www.molllust.com *
>> * M'era Luna Newcomer 2013! *
>> ************************************************
>>
>> --------------------------------------------------------------------------
>> ----
>> Learn Graph Databases - Download FREE O'Reilly Book
>> "Graph Databases" is the definitive new guide to graph databases and their
>> applications. Written by three acclaimed leaders in the field,
>> this first edition is now available. Download your free book today!
>> http://p.sf.net/sfu/13534_NeoTech
>> _______________________________________________
>> dotNetRDF-Support mailing list
>> dot...@li...
>> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support
>
>
>
>
>
> ------------------------------------------------------------------------------
> Learn Graph Databases - Download FREE O'Reilly Book
> "Graph Databases" is the definitive new guide to graph databases and their
> applications. Written by three acclaimed leaders in the field,
> this first edition is now available. Download your free book today!
> http://p.sf.net/sfu/13534_NeoTech
> _______________________________________________
> dotNetRDF-Support mailing list
> dot...@li...
> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support
>
--
************************************************
* Universität Leipzig, Institut für Informatik *
* Abteilung Betriebliche Informationssysteme *
* http://bis.informatik.uni-leipzig.de *
* Tel.: 0341 / 97 32 256 *
* *
* ========== Opera Metal: molllust =========== *
* http://www.molllust.com *
* M'era Luna Newcomer 2013! *
************************************************
|
×
Want the latest updates on software, tech news, and AI?
Get latest updates about software, tech news, and AI from SourceForge directly in your inbox once a month.
Thanks for helping keep SourceForge clean.
X