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  1. Hadoop HDFS
  2. HDFS-4697

short-circuit reads do not honor readahead settings

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Details

    • Bug
    • Status: Closed
    • Minor
    • Resolution: Duplicate
    • 2.0.3-alpha
    • 2.3.0
    • hdfs-client
    • None

    Description

      Neither the new nor the legacy short-circuit read implementations honor dfs.datanode.readahead.bytes. This can result in scenarios where non-short-circuit reads are faster for long reads, simply because they are doing more readahead, and SCR is not. We should do readahead in both cases if it is configured.

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          duplicates

          Sub-task - The sub-task of the issue HDFS-5634 allow BlockReaderLocal to switch between checksumming and not

          • Major - Major loss of function.
          • Closed

          Improvement - An improvement or enhancement to an existing feature or task. HDFS-3228 Use fadvise in local read path

          • Major - Major loss of function.
          • Open

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              cmccabe Colin McCabe
              cmccabe Colin McCabe
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              Dates

                Created:
                Updated:
                Resolved: