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  1. Hadoop Common
  2. HADOOP-9747 Reduce unnecessary UGI synchronization
  3. HADOOP-9749

Remove synchronization for UGI.getCurrentUser

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Details

    • Sub-task
    • Status: Resolved
    • Critical
    • Resolution: Duplicate
    • 0.23.0, 2.0.0-alpha, 3.0.0-alpha1
    • None
    • security
    • None

    Description

      HADOOP-7854 added synchronization to getCurrentUser due to ConcurrentModificationExceptions. This degrades NN call handler performance.

      The problem was not well understood at the time, but it's caused by a collision between relogin and getCurrentUser due to a bug in Krb5LoginModule. Avoiding the collision will allow removal of the synchronization.

      Attachments

        1. HADOOP-9749.trunk.2.patch
          20 kB
          Daryn Sharp
        2. HADOOP-9749.trunk.patch
          20 kB
          Kihwal Lee
        3. HADOOP-9749.branch-2.patch
          20 kB
          Daryn Sharp
        4. HADOOP-9749.trunk.patch
          20 kB
          Daryn Sharp

        Issue Links

          relates to

          Improvement - An improvement or enhancement to an existing feature or task. HDFS-5010 Reduce the frequency of getCurrentUser() calls from namenode

          • Major - Major loss of function.
          • Closed
          requires

          Sub-task - The sub-task of the issue HADOOP-9852 UGI login user keytab and principal should not be static

          • Major - Major loss of function.
          • Resolved

          Sub-task - The sub-task of the issue HADOOP-9856 Avoid Krb5LoginModule.logout issue

          • Major - Major loss of function.
          • Resolved

          Activity

            People

              daryn Daryn Sharp
              daryn Daryn Sharp
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              Dates

                Created:
                Updated:
                Resolved: