hadoop-hdfs-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Hairong Kuang (Created) (JIRA)" <j...@apache.org>
Subject [jira] [Created] (HDFS-2421) Improve the concurrency of SerialNumberMap in NameNode
Date Sat, 08 Oct 2011 16:34:29 GMT
Improve the concurrency of  SerialNumberMap in NameNode

                 Key: HDFS-2421
                 URL: https://issues.apache.org/jira/browse/HDFS-2421
             Project: Hadoop HDFS
          Issue Type: Improvement
          Components: name-node
            Reporter: Hairong Kuang
            Assignee: Weiyan Wang
             Fix For: 0.24.0

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

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira


View raw message