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  1. Cassandra
  2. CASSANDRA-7938

Releases prior to 2.0 gratuitously invalidate buffer cache

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    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Low
    • Resolution: Won't Fix
    • Fix Version/s: 1.2.19
    • Component/s: None
    • Labels:
      None
    • Severity:
      Low

      Description

      RandomAccessReader gratuitously invalidates the buffer cache in releases prior to 2.0.

      Additionally, Linux 3.X kernels spend 30% of CPU time in book keeping for the invalidated pages as captured by CPU flame graphs.

      fadvise DONT_NEED should never be called for files other than the commit log segments.

      https://github.com/apache/cassandra/blob/cassandra-2.1/src/java/org/apache/cassandra/io/util/RandomAccessReader.java#L168

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        1. 7938.txt
          0.9 kB
          T Jake Luciani

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            • Assignee:
              Unassigned
              Reporter:
              mstump Matt Stump
              Reviewers:
              Matt Stump
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              Dates

              • Created:
                Updated:
                Resolved: