[Pellet-users] Cannot stop timer exception

[Michael Smith]

On Thu, 2008-06-26 at 12:32 -0500, Schmitz, Jeffrey A wrote:

>    I'm trying to run a construct query on a Jena/Pellet Mysql backed
> model.  The query runs fine from top-braid composer's SPARQL window with
> inferencing on, but when I try to run it from my java/jena app, I get
> the following exception.  I don't know where to begin to look for the
> problem, any ideas?  I do run other queries on this model fine from my
> app, it's just one particular query that is causing problems, and again,
> it runs fine from top braid composer.

To address this we probably need to see to calling code, the data, and
the SPARQL query.

> java.lang.UnsupportedOperationException: Cannot stop timer 'rule-choose'
> which is not started!
> 	at org.mindswap.pellet.utils.Timer.stop(Timer.java:139)
> 	at org.mindswap.pellet.SROIQStrategy.complete(SROIQStrategy.java:179)
> 	at org.mindswap.pellet.ABox.isConsistent(ABox.java:1605)
...
> 	at com.hp.hpl.jena.graph.query.PatternStageBase$Work.run(PatternStageBase.java:104)
> 	at com.hp.hpl.jena.graph.query.PatternStageBase$PatternStageThread.run(PatternStageBase.java:88)

Is it possible that you have multiple threads concurrently accessing the
Pellet backed inference graph?  It is very likely this would lead to
problems, see the faq entry on concurrency at [1].
-- 
Mike Smith

Clark & Parsia

[1] http://pellet.owldl.com/faq/how-do-i-use-pellet-with-jena-concurrently/