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  1. Blazegraph (by SYSTAP)
  2. BLZG-942

OutOfMemoryError instead of Timeout for SPARQL Property Paths

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    Details

    • Type: Bug
    • Status: Done
    • Resolution: Done
    • Affects Version/s: BIGDATA_RELEASE_1_3_0
    • Fix Version/s: None
    • Component/s: B+Tree

      Description

      If Bigdata gets an ArbitraryLengthPropertyPath operator, it ignores a set query timeout and runs into an OutOfMemory Error instead.
      This happens for a query like:
      {{

      {SELECT * WHERE \{ ?s rdf:type* ?o } LIMIT 1}

      }}

      The problem is discussed in this thread: http://sourceforge.net/p/bigdata/discussion/676946/thread/0df3c970/

      I got aware of this problem because the service http://sparqles.okfn.org/endpoint/http%3A%2F%2Flod.b3kat.de%2Fsparql shows no SPARQL compatibility at all. It regularly kills our 2 Bigdata instances every sunday morning by checking various SPARQL Features. I assume, after the crash, it gets no response any more and indicates all features are not working.

      See BLZG-404 (Deadlines do not play well with GROUP_BY, ORDER_BY, etc.)
      See BLZG-857 (Query timeout only checked at operator start/stop)

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            Assignee:
            bryanthompson bryanthompson
            Reporter:
            andreaskahl andreaskahl
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              Updated:
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