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  1. IMPALA
  2. IMPALA-4580

Crash when FETCH_FIRST exhausts result set cache

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Blocker
    • Resolution: Fixed
    • Affects Version/s: Impala 2.8.0
    • Fix Version/s: Impala 2.8.0
    • Component/s: Backend
    • Labels:
      None

      Description

      The following sequence can lead to a crash:

      1. Client sets result cache size to N
      2. Client issues query with #results < N
      3. Client fetches all results, triggering eos and tearing down Coordinator::root_sink_.
      4. Client restarts query with FETCH_FIRST.
      5. Client reads all results again. After cache is exhausted, Coordinator::GetNext() is called to detect eos condition again.
      6. GetNext() hits DCHECK(root_sink_ != nullptr).

      Either the QES or the coordinator need to remember that eos was once true, and turn GetNext() into a no-op if so.

        Activity

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        henryr Henry Robinson added a comment - Fixed in https://github.com/apache/incubator-impala/commit/b9034ea0d54ad40e11b482b577362ceee3768f1e

          People

          • Assignee:
            henryr Henry Robinson
            Reporter:
            henryr Henry Robinson
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            Dates

            • Created:
              Updated:
              Resolved:

              Development