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  1. IMPALA
  2. IMPALA-5393

Regexp should use THREAD_LOCAL context rather than FRAGMENT_LOCAL

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Details

    • Improvement
    • Status: Resolved
    • Minor
    • Resolution: Fixed
    • Impala 2.8.0
    • Impala 3.3.0
    • Backend
    • None

    Description

      The RE2 library uses mutex locking around some internal state structures. This causes severe lock contention and lack of CPU scaling on the regexp string function.

      Switching to THREAD_LOCAL context will remove the contention.

      We could add a query option to select between FRAGMENT_LOCAL vs THREAD_LOCAL but that seems overkill as the context is not huge.

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              tlipcon Todd Lipcon
              djcameron Doug Cameron
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                Created:
                Updated:
                Resolved: