[ 
https://issues.apache.org/jira/browse/DRILL-4065?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14999716#comment-14999716
 ] 

Jacques Nadeau commented on DRILL-4065:
---------------------------------------

I'm not an expert here but it looks like the FileSystem cache keys off of 
UGI.subject + URI + conf. The cache uses identity comparison for subject. Since 
we don't close FileSystem objects (and each FileSystem object gets at least one 
thread), this could be a major problem for production customers, not just the 
test cases. I'm not sure if the cache behavior changed for Hadoop 2.7 vs 2.4 
that we upgraded in this release. Others that know the FileSystem code better 
might have additional insights.

> ImpersonationUtil always creates new UserGroupInformation (thus new 
> FileSystem objects), causing excessive number of threads
> ----------------------------------------------------------------------------------------------------------------------------
>
>                 Key: DRILL-4065
>                 URL: https://issues.apache.org/jira/browse/DRILL-4065
>             Project: Apache Drill
>          Issue Type: Bug
>            Reporter: Jacques Nadeau
>            Assignee: Venki Korukanti
>             Fix For: 1.3.0
>
>         Attachments: DRILL-4065.patch
>
>




--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to