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  1. Blazegraph (by SYSTAP)
  2. BLZG-641 Improve load performance
  3. BLZG-1569

Concurrent modification error in load-performance branch?

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    Details

    • Type: Sub-task
    • Status: Done
    • Priority: Medium
    • Resolution: Done
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: None
    • Labels:
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      Description

      I sometimes see what looks like a concurrent modification error in the load-performance branch using the DataLoader with maxReaders > 1. This ticket exists to track the issue and see if we can get to a root cause. This stack trace is on

          @Override
          public long indexOf(final byte[] key) {
      
              assert !deleted; // <== assertion is thrown here.
      
              btree.touch(this);
      

      The stack trace is:

      java.util.concurrent.ExecutionException: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.AssertionError
      	at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:252)
      	at java.util.concurrent.FutureTask.get(FutureTask.java:111)
      	at com.bigdata.rdf.spo.SPORelation.logFuture(SPORelation.java:2298)
      	at com.bigdata.rdf.spo.SPORelation.insert(SPORelation.java:2253)
      	at com.bigdata.rdf.store.AbstractTripleStore.addStatements(AbstractTripleStore.java:4207)
      	at com.bigdata.rdf.rio.StatementBuffer$Batch.writeSPOs(StatementBuffer.java:1944)
      	at com.bigdata.rdf.rio.StatementBuffer$Batch.addStatements(StatementBuffer.java:1795)
      	at com.bigdata.rdf.rio.StatementBuffer$Batch.writeNow(StatementBuffer.java:1681)
      	at com.bigdata.rdf.rio.StatementBuffer$Batch.access$800(StatementBuffer.java:1491)
      	at com.bigdata.rdf.rio.StatementBuffer$DrainQueueCallable.drainQueueAndMergeBatches(StatementBuffer.java:809)
      	at com.bigdata.rdf.rio.StatementBuffer$DrainQueueCallable.call(StatementBuffer.java:742)
      	at com.bigdata.rdf.rio.StatementBuffer$DrainQueueCallable.call(StatementBuffer.java:711)
      	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
      	at java.util.concurrent.FutureTask.run(FutureTask.java:166)
      	at com.bigdata.util.concurrent.LatchedExecutor$1.run(LatchedExecutor.java:121)
      	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
      	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
      	at java.lang.Thread.run(Thread.java:724)
      Caused by: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.AssertionError
      	at com.bigdata.btree.proc.AbstractKeyArrayIndexProcedure.apply(AbstractKeyArrayIndexProcedure.java:479)
      	at com.bigdata.btree.UnisolatedReadWriteIndex.submit(UnisolatedReadWriteIndex.java:723)
      	at com.bigdata.rdf.spo.SPOIndexWriter.call(SPOIndexWriter.java:363)
      	at com.bigdata.rdf.spo.SPOIndexWriter.call(SPOIndexWriter.java:68)
      	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
      	at java.util.concurrent.FutureTask.run(FutureTask.java:166)
      	... 3 more
      Caused by: java.util.concurrent.ExecutionException: java.lang.AssertionError
      	at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:252)
      	at java.util.concurrent.FutureTask.get(FutureTask.java:111)
      	at com.bigdata.btree.proc.AbstractKeyArrayIndexProcedure.applyMultipleReadersOneWriter(AbstractKeyArrayIndexProcedure.java:625)
      	at com.bigdata.btree.proc.AbstractKeyArrayIndexProcedure.apply(AbstractKeyArrayIndexProcedure.java:475)
      	... 8 more
      Caused by: java.lang.AssertionError
      	at com.bigdata.btree.Node.indexOf(Node.java:965)
      	at com.bigdata.btree.Node.indexOf(Node.java:988)
      	at com.bigdata.btree.AbstractBTree.indexOf(AbstractBTree.java:2498)
      	at com.bigdata.btree.proc.AbstractKeyArrayIndexProcedure$ReaderTask.doSimpleBTree(AbstractKeyArrayIndexProcedure.java:1107)
      	at com.bigdata.btree.proc.AbstractKeyArrayIndexProcedure$ReaderTask.call(AbstractKeyArrayIndexProcedure.java:922)
      	at com.bigdata.btree.proc.AbstractKeyArrayIndexProcedure$ReaderTask.call(AbstractKeyArrayIndexProcedure.java:854)
      
      

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              Assignee:
              bryanthompson bryanthompson
              Reporter:
              bryanthompson bryanthompson
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                Dates

                Created:
                Updated:
                Resolved: