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  1. Hadoop HDFS
  2. HDFS-11738

Hedged pread takes more time when block moved from initial locations

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    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 2.9.0, 3.0.0-beta1, 2.8.3
    • Component/s: hdfs-client
    • Labels:
      None

      Description

      Scenario :
      Same as HDFS-11708.

      During Hedge read,
      1. First two locations fails to read the data in hedged mode.
      2. chooseData refetches locations and adds a future to read from DN3.
      3. after adding future to DN3, main thread goes for refetching locations in loop and stucks there till all 3 retries to fetch locations exhausted, which consumes ~20 seconds with exponential retry time.

        Attachments

        1. HDFS-11738-01.patch
          28 kB
          Vinayakumar B
        2. HDFS-11738-02.patch
          14 kB
          Vinayakumar B
        3. HDFS-11738-03.patch
          13 kB
          Vinayakumar B
        4. HDFS-11738-04.patch
          14 kB
          Vinayakumar B
        5. HDFS-11738-05.patch
          12 kB
          Vinayakumar B
        6. HDFS-11738-branch-2-committed.patch
          13 kB
          Vinayakumar B
        7. HDFS-11738-branch-2.8-committed.patch
          12 kB
          Vinayakumar B

          Issue Links

          depends upon

          Bug - A problem which impairs or prevents the functions of the product. HDFS-11708 Positional read will fail if replicas moved to different DNs after stream is opened

          • Critical - Crashes, loss of data, severe memory leak.
          • Resolved

            Activity

              People

              • Assignee:
                vinayakumarb Vinayakumar B
                Reporter:
                vinayakumarb Vinayakumar B
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                Dates

                • Created:
                  Updated:
                  Resolved: