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  1. Hadoop Common
  2. HADOOP-3280

virtual address space limits break streaming apps

    Details

    • Type: Bug
    • Status: Closed
    • Priority: Blocker
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.17.0
    • Component/s: None
    • Labels:
      None
    • Hadoop Flags:
      Incompatible change, Reviewed
    • Release Note:
      This patch adds the mapred.child.ulimit to limit the virtual memory for children processes to the given value.

      Description

      HADOOP-2765 added a mandatory, hard virtual address space limit to streaming apps based on the Java process's -Xmx setting.

      This makes it impossible to run a 64-bit streaming app that needs large address spaces under a 32-bit JVM, even if one is otherwise willing to dramatically increase the -Xmx setting without cause. Also, unlike Java's -Xmx limit, the virtual address space limit for an arbitrary UNIX process does not necessarily correspond to RAM usage, so it's likely to be a relatively difficult to configure limit.

      2765 was originally opened to allow an optional wrapper script around streaming tasks, one use case for which was setting a ulimit. That approach seems much less intrusive and more flexible than the final implementation. The ulimit can also be trivially set by the streaming task itself without any support from Hadoop.

      Marking this as an 0.17 blocker because it will break deployed apps and there is no workaround available.

        Attachments

        1. patch-3280-3.txt
          18 kB
          Amareshwari Sriramadasu
        2. patch-3280-2.txt
          18 kB
          Amareshwari Sriramadasu
        3. patch-3280-1.txt
          18 kB
          Amareshwari Sriramadasu
        4. patch-3280.txt
          14 kB
          Amareshwari Sriramadasu
        5. patch-3280.txt
          15 kB
          Amareshwari Sriramadasu
        6. HADOOP-3280_3_20080425.patch
          18 kB
          Arun C Murthy
        7. HADOOP-3280_2_20080424.patch
          18 kB
          Arun C Murthy
        8. HADOOP-3280_1_20080423.patch
          7 kB
          Arun C Murthy
        9. HADOOP-3280_0_20080418.patch
          2 kB
          Arun C Murthy

          Activity

            People

            • Assignee:
              acmurthy Arun C Murthy
              Reporter:
              rickcox Rick Cox
            • Votes:
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              Watchers:
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              Dates

              • Created:
                Updated:
                Resolved: