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  1. Hadoop HDFS
  2. HDFS-8873

Allow the directoryScanner to be rate-limited

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    • Target Version/s:
    • Hadoop Flags:
      Reviewed

      Description

      The new 2-level directory layout can make directory scans expensive in terms of disk seeks (see HDFS-8791) for details.

      It would be good if the directoryScanner() had a configurable duty cycle that would reduce its impact on disk performance (much like the approach in HDFS-8617).

      Without such a throttle, disks can go 100% busy for many minutes at a time (assuming the common case of all inodes in cache but no directory blocks cached, 64K seeks are required for full directory listing which translates to 655 seconds)

        Attachments

        1. HDFS-8873.001.patch
          56 kB
          Daniel Templeton
        2. HDFS-8873.002.patch
          57 kB
          Daniel Templeton
        3. HDFS-8873.003.patch
          56 kB
          Daniel Templeton
        4. HDFS-8873.004.patch
          57 kB
          Daniel Templeton
        5. HDFS-8873.005.patch
          29 kB
          Daniel Templeton
        6. HDFS-8873.006.patch
          30 kB
          Daniel Templeton
        7. HDFS-8873.007.patch
          34 kB
          Daniel Templeton
        8. HDFS-8873.008.patch
          34 kB
          Daniel Templeton
        9. HDFS-8873.009.patch
          34 kB
          Daniel Templeton
        10. HDFS-8873-branch-2.7.009.patch
          34 kB
          Erik Krogen

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              • Assignee:
                templedf Daniel Templeton
                Reporter:
                nroberts Nathan Roberts
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                • Created:
                  Updated:
                  Resolved: