[ 
https://issues.apache.org/jira/browse/YARN-10996?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17437181#comment-17437181
 ] 

Andras Gyori commented on YARN-10996:
-------------------------------------

It is important to check each location individually, as laborously replacing 
getUser with getUserAndAddIfAbsent could introduce a memory leak as:
 * users are only removed when an application attempt is removed belonging to 
the user and the user has no more application left
 * if we reinsert a user without an application, that user will never be 
removed again, thus introducing a leak

> Fix race condition of User object acquisitions
> ----------------------------------------------
>
>                 Key: YARN-10996
>                 URL: https://issues.apache.org/jira/browse/YARN-10996
>             Project: Hadoop YARN
>          Issue Type: Bug
>            Reporter: Andras Gyori
>            Assignee: Andras Gyori
>            Priority: Major
>
> UserManager is highly susceptible of removing users that are queried later. 
> This race condition produces NPE similar to YARN-10934. A non-exhaustive list 
> of these locations are:
> - LeafQueue.getTotalPendingResourcesConsideringUserLimit
> - UsersManager.computeUserLimit
>  



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

---------------------------------------------------------------------
To unsubscribe, e-mail: yarn-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: yarn-issues-h...@hadoop.apache.org

Reply via email to