hadoop-hdfs-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Kihwal Lee (JIRA)" <j...@apache.org>
Subject [jira] [Resolved] (HDFS-1775) getContentSummary should hold the FSNamesystem readlock
Date Fri, 12 Jul 2013 18:35:53 GMT

     [ https://issues.apache.org/jira/browse/HDFS-1775?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel

Kihwal Lee resolved HDFS-1775.

    Resolution: Duplicate
> getContentSummary should hold the FSNamesystem readlock
> -------------------------------------------------------
>                 Key: HDFS-1775
>                 URL: https://issues.apache.org/jira/browse/HDFS-1775
>             Project: Hadoop HDFS
>          Issue Type: Bug
>            Reporter: Dmytro Molkov
>            Assignee: Dmytro Molkov
>            Priority: Minor
> Right now the getContentSummary call on the namenode only holds the FSDirectory lock,
but not the FSNamesystem lock. What we are seeing because of that is: 
> 1) getContentSummary takes the read lock on FSDirectory 
> 2) the write operation comes and takes a write lock on FSNamesystem and waits for getContentSummary
to finish to get a write lock on FSDirectory
> As a result other read operations can't be executed. Since getContentSummary can take
a while to execute on large directories, the performance would be improved if we hold a readlock
while doing that.

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

View raw message