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  1. Hadoop HDFS
  2. HDFS-6840

Clients are always sent to the same datanode when read is off rack

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Critical
    • Resolution: Fixed
    • Affects Version/s: 2.5.0
    • Fix Version/s: 2.6.0
    • Component/s: None
    • Labels:
      None
    • Target Version/s:

      Description

      After HDFS-6268 the sorting order of block locations is deterministic for a given block and locality level (e.g.: local, rack. off-rack), so off-rack clients all see the same datanode for the same block. This leads to very poor behavior in distributed cache localization and other scenarios where many clients all want the same block data at approximately the same time. The one datanode is crushed by the load while the other replicas only handle local and rack-local requests.

        Attachments

        1. hdfs-6840.001.patch
          18 kB
          Andrew Wang
        2. hdfs-6840.002.patch
          19 kB
          Andrew Wang
        3. hdfs-6840.003.patch
          19 kB
          Andrew Wang
        4. hdfs-6840.branch-2.patch
          28 kB
          Andrew Wang

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              • Assignee:
                andrew.wang Andrew Wang
                Reporter:
                jlowe Jason Darrell Lowe
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                Dates

                • Created:
                  Updated:
                  Resolved: