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  1. Couchbase Server
  2. MB-44944

Hang in Intersect Scan

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Details

    • Bug
    • Status: Closed
    • Major
    • Resolution: Fixed
    • Cheshire-Cat, 6.6.1
    • 6.6.2, 7.0.0
    • query
    • Untriaged
    • 1
    • Unknown

    Description

      Repro:

      Install  6.6.1-9213
      Install travel-sample
      CREATE INDEX `def_type` ON `travel-sample`(`type`);  -- Already there
      CREATE INDEX `ix10` ON `travel-sample`(`country`);
      CREATE INDEX `ix11` ON `travel-sample`(`id`);
       
      \set -timeout "1ms";
      select type, country, x FROM `travel-sample` where type = "airline" AND country = "United States" and id = "abc";
       
      repeat select statement many/many times at some point you will see hang.
      Check go routine dump and you similar like below.
      

      goroutine 7624472 [semacquire, 3633 minutes]:
      sync.runtime_Semacquire(0xc00cf609ac)
              /home/couchbase/.cbdepscache/exploded/x86_64/go-1.11.4/go/src/runtime/sema.go:56 +0x39
      sync.(*WaitGroup).Wait(0xc00cf609ac)
              /home/couchbase/.cbdepscache/exploded/x86_64/go-1.11.4/go/src/sync/waitgroup.go:130 +0x64
      github.com/couchbase/query/execution.(*valueExchange).retrieveChildNoStop(0xc00cf60900, 0xc00cf606c0)
              /home/couchbase/jenkins/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/query/execution/exchange.go:428 +0x85
      github.com/couchbase/query/execution.(*base).childrenWaitNoStop(0xc00cf60900, 0xc004a69e00, 0x2, 0x10)
              /home/couchbase/jenkins/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/query/execution/base.go:741 +0x1c7
      github.com/couchbase/query/execution.(*IntersectScan).RunOnce.func1()
              /home/couchbase/jenkins/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/query/execution/scan_intersect.go:146 +0x7f6
      github.com/couchbase/query/util.(*Once).Do(0xc00cf60a08, 0xc0047a6f88)
              /home/couchbase/jenkins/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/query/util/sync.go:54 +0x4a
      github.com/couchbase/query/execution.(*IntersectScan).RunOnce(0xc00cf60900, 0xc006625b00, 0x0, 0x0)
              /home/couchbase/jenkins/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/query/execution/scan_intersect.go:61 +0x82
      created by github.com/couchbase/query/execution.(*base).runConsumer.func1
              /home/couchbase/jenkins/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/query/execution/base.go:805 +0x2d6
       
      
      

      Attachments

        1. f.log
          13.76 MB
        2. g.log
          12.94 MB
        For Gerrit Dashboard: MB-44944
        # Subject Branch Project Status CR V

        Activity

          Build couchbase-server-7.0.0-4705 contains query commit 5db18cb with commit message:
          MB-44944 intersect scan hangs on timeout

          build-team Couchbase Build Team added a comment - Build couchbase-server-7.0.0-4705 contains query commit 5db18cb with commit message: MB-44944 intersect scan hangs on timeout

          Wayne Siu lets take this in 6.6.2.

          mihir.kamdar Mihir Kamdar (Inactive) added a comment - Wayne Siu lets take this in 6.6.2.

          Build couchbase-server-6.6.2-9568 contains query commit 023958a with commit message:
          MB-44944 intersect scan hangs on timeout

          build-team Couchbase Build Team added a comment - Build couchbase-server-6.6.2-9568 contains query commit 023958a with commit message: MB-44944 intersect scan hangs on timeout
          pierre.regazzoni Pierre Regazzoni added a comment - - edited

          Verified hang is not happening on 7.0.0-4705 by running query 50+ times. Could not see hang. I could repro on 4678 for comparison.

          I am still waiting for 6.6.2 build to complete and will post findings then.

          pierre.regazzoni Pierre Regazzoni added a comment - - edited Verified hang is not happening on 7.0.0-4705 by running query 50+ times. Could not see hang. I could repro on 4678 for comparison. I am still waiting for 6.6.2 build to complete and will post findings then.

          Also verified on 6.6.2-9569. Ran query 50+ times.

          pierre.regazzoni Pierre Regazzoni added a comment - Also verified on 6.6.2-9569. Ran query 50+ times.

          People

            pierre.regazzoni Pierre Regazzoni
            Sitaram.Vemulapalli Sitaram Vemulapalli
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            Dates

              Created:
              Updated:
              Resolved:

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