Hi Andy regarding query timeouts, I see that ARQ 2.8.8 mentions the new timeout feature in the ChangeLog. Sorry, I wasn't able to follow all the details of the list discussion of timeouts a few weeks back.
Is the new timeout feature already integrated in Joseki? (Given release date of Joseki 3.4.3 I'm guessing not). Is there an example or some documentation that shows how to make use of QueryExecution.setTimeout from Joseki? Or is it implemented in a Joseki code branch somewhere? It will be very useful and I'm keen to give it a try. Many thanks Bill On 2 May 2011, at 14:43, Andy Seaborne wrote: > > > On 02/05/11 13:22, Mohamed Morsey wrote: >> Hi all, >> >> I'm doing a kind of benchmarking on triple stores using DBpedia dataset, >> and I'm using Jena-TDB as one of them. >> I've installed Joseki server, and configured its config file to use this >> dataset. >> But when I try to benchmark Jena through Joseki, the performance of >> Jena-TDB is very low and too many queries time out. > > How do they timeout? > > The newest TDB has query timeouts which means when a query does timeout, it > really does stop. Just forgetting about it does not necessarily stop it > executing. > >> I've assigned 8GB of memory to Joseki. > > This will slow the system down. > > TDB does not use the heap for DB caches - in 64 bit mode, it uses memory > mapped files. If you use a large heap, there is less RAM for swapped in > memory mapped file space. > >> I've also tried to query the DBpedia graph directly using >> "TDBFactory.createDataset" and "QueryExecutionFactory.create", but when >> I iterate through the returned "ResultSet" either with simple loop or >> with "ResultSetFormatter.consume", it works only for the first few >> queries and afterwards an Exception of type >> "com.hp.hpl.jena.tdb.base.block.BlockException" is always thrown. > > Stacktrace? > > That looks like a bug somewhere, either in the concurrency policy or an > already corrupt database. > > Which versions are you using? > > Andy > >> >> Any help will be appreciated. >>
