Hello,
We’re facing an issue with Jena reading n-triples stream over HTTP. In fact,
our application hangs entirely while executing this piece of code:
Model sub = ModelFactory.createDefaultModel();
TypedInputStream stream = HttpOp.execHttpGet(requestURL,
WebContent.contentTypeNTriples, createHttpClient(auth), null)
// The following part sometimes hangs:
RDFParser.create()
.source(stream)
.lang(Lang.NTRIPLES)
.errorHandler(ErrorHandlerFactory.errorHandlerStrict)
.parse(sub.getGraph());
// This point is not reached
The issue is not persistent, moreover it happens infrequently. When it occurs,
the RDF store server (we use Dydra for that) logs a successful HTTP 200
response for our call (truncated for readability):
HTTP/1.1" 200 3072/55397664 10.676/10.828 "application/n-triples" "-" "-"
"Apache-Jena-ARQ/3.17.0" "127.0.0.1:8104"
So it looks like the RDF store successfully executes the SPARQL query, responds
with HTTP 200 and starts transferring the data with the chunked encoding. Then
something goes wrong when Jena processes the input stream. I expect there might
be some timeout behind the scenes while Jena reads the stream, and it causes it
to wait indefinitely. At the same time ErrorHandlerFactory.errorHandlerStrict
does not help at all – no errors are logged.
Is there a way to configure the timeout behavior for the underlying Jena logic
of processing HTTP stream? Ideally we want to abort the request if it times out
and then retry it a few times until it succeeds.
Met vriendelijke groet, with kind regards,
Ivan Lagunov
Technical Lead / Software Architect
Skype: lagivan
Semaku B.V.
Torenallee 20 (SFJ3D) • 5617 BC Eindhoven • www.semaku.com
