Hadoop HDFS
  1. Hadoop HDFS
  2. HDFS-2421

Improve the concurrency of SerialNumberMap in NameNode

    Details

    • Type: Improvement Improvement
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.23.3, 2.0.2-alpha
    • Component/s: namenode
    • Labels:
      None
    • Hadoop Flags:
      Reviewed

      Description

      After enabled permission checking in our HDFS test cluster, our benchmark observed a significant reduced concurrency in NameNode. Investigation showed that most threads were blocked at acquiring the lock of org.apache.hadoop.hdfs.server.namenode.SerialNumberManager$SerialNumberMap. We used concurrentHashMap to replace Hashmap + synchronized methods, which greatly improved the situation.

      1. HDFS-2421.patch
        2 kB
        Jing Zhao
      2. performance_10000_op.png
        59 kB
        Jing Zhao
      3. performance_100000_op.png
        48 kB
        Jing Zhao
      4. performance_SerialNumberManager.png
        55 kB
        Jing Zhao
      5. TestSerialNumberManager.java
        4 kB
        Jing Zhao

        Issue Links

          Activity

          Hairong Kuang created issue -
          Jing Zhao made changes -
          Field Original Value New Value
          Attachment HDFS-2421.patch [ 12540993 ]
          Attachment TestSerialNumberManager.java [ 12540994 ]
          Attachment performance_SerialNumberManager.png [ 12540995 ]
          Jing Zhao made changes -
          Link This issue relates to HDFS-3805 [ HDFS-3805 ]
          Jing Zhao made changes -
          Attachment performance_100000_op.png [ 12541119 ]
          Jing Zhao made changes -
          Attachment HDFS-2421.patch [ 12540993 ]
          Jing Zhao made changes -
          Attachment performance_10000_op.png [ 12541120 ]
          Jing Zhao made changes -
          Attachment HDFS-2421.patch [ 12541170 ]
          Suresh Srinivas made changes -
          Assignee Weiyan Wang [ weiyan ] Jing Zhao [ jingzhao ]
          Suresh Srinivas made changes -
          Status Open [ 1 ] Patch Available [ 10002 ]
          Tsz Wo Nicholas Sze made changes -
          Hadoop Flags Reviewed [ 10343 ]
          Tsz Wo Nicholas Sze made changes -
          Status Patch Available [ 10002 ] Resolved [ 5 ]
          Fix Version/s 2.2.0-alpha [ 12322472 ]
          Fix Version/s 0.24.0 [ 12317653 ]
          Resolution Fixed [ 1 ]
          Daryn Sharp made changes -
          Fix Version/s 0.23.3 [ 12320052 ]
          Arun C Murthy made changes -
          Status Resolved [ 5 ] Closed [ 6 ]

            People

            • Assignee:
              Jing Zhao
              Reporter:
              Hairong Kuang
            • Votes:
              0 Vote for this issue
              Watchers:
              13 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved:

                Development