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  1. Hadoop Common
  2. HADOOP-8088

User-group mapping cache incorrectly does negative caching on transient failures

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Details

    • Bug
    • Status: Closed
    • Major
    • Resolution: Fixed
    • 0.20.205.0, 1.0.0, 1.1.0, 0.23.1, 0.24.0
    • 0.23.3, 2.0.2-alpha
    • security
    • None

    Description

      We've seen a case where some getGroups() calls fail when the ldap server or the network is having transient failures. Looking at the code, the shell-based and the JNI-based implementations swallow exceptions and return an empty or partial list. The caller, Groups#getGroups() adds this likely empty list into the mapping cache for the user. This will function as negative caching until the cache expires. I don't think we want negative caching here, but even if we do, it should be intelligent enough to distinguish transient failures from ENOENT. The log message in the jni-based impl also needs an improvement. It should print what exception it encountered instead of just saying one happened.

      Attachments

        1. hadoop-8088-branch-1.patch
          9 kB
          Kihwal Lee
        2. hadoop-8088-trunk.patch
          9 kB
          Kihwal Lee
        3. hadoop-8088-trunk.patch
          9 kB
          Kihwal Lee
        4. hadoop-8088-branch-1.patch
          5 kB
          Kihwal Lee
        5. hadoop-8088-trunk.patch
          5 kB
          Kihwal Lee

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              kihwal Kihwal Lee
              kihwal Kihwal Lee
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                Created:
                Updated:
                Resolved: