[ https://issues.apache.org/jira/browse/HDFS-1093?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
dhruba borthakur updated HDFS-1093: ----------------------------------- Status: Patch Available (was: Open) Fix Version/s: 0.22.0 > Improve namenode scalability by splitting the FSNamesystem synchronized > section in a read/write lock > ---------------------------------------------------------------------------------------------------- > > Key: HDFS-1093 > URL: https://issues.apache.org/jira/browse/HDFS-1093 > Project: Hadoop HDFS > Issue Type: Improvement > Components: name-node > Reporter: dhruba borthakur > Assignee: dhruba borthakur > Fix For: 0.22.0 > > Attachments: NNreadwriteLock.txt, NNreadwriteLock_trunk_1.txt, > NNreadwriteLock_trunk_2.txt, NNreadwriteLock_trunk_3.txt, > NNreadwriteLock_trunk_4.txt > > > Most critical data structures in the NameNode (NN) are protected by a > syncronized methods in the FSNamesystem class. This essentially makes > critical code paths in the NN single-threaded. However, a large percentage of > the NN calls are listStatus, getBlockLocations, etc which do not change > internal data structures at all, these are read-only calls. If we change the > FSNamesystem lock to a read/write lock, many of the above operations can > occur in parallel, thus improving the scalability of the NN. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.