hadoop-yarn-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Karthik Kambatla (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (YARN-2608) FairScheduler may hung due to two potential deadlocks
Date Fri, 26 Sep 2014 00:26:33 GMT

    [ https://issues.apache.org/jira/browse/YARN-2608?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14148538#comment-14148538
] 

Karthik Kambatla commented on YARN-2608:
----------------------------------------

+1. Committing this. 

> FairScheduler may hung due to two potential deadlocks
> -----------------------------------------------------
>
>                 Key: YARN-2608
>                 URL: https://issues.apache.org/jira/browse/YARN-2608
>             Project: Hadoop YARN
>          Issue Type: Bug
>            Reporter: Wei Yan
>            Assignee: Wei Yan
>         Attachments: YARN-2608-1.patch, YARN-2608-2.patch, YARN-2608-3.patch
>
>
> Two potential deadlocks exist inside the FairScheduler.
> 1. AllocationFileLoaderService would reload the queue configuration, which calls FairScheduler.AllocationReloadListener.onReload()
function. And require *FairScheduler's lock*; 
> {code}
>   public void onReload(AllocationConfiguration queueInfo) {
>       synchronized (FairScheduler.this) {
>           ....
>       }
>   }
> {code}
> after that, it would require the *QueueManager's queues lock*.
> {code}
>   private FSQueue getQueue(String name, boolean create, FSQueueType queueType) {
>       name = ensureRootPrefix(name);
>       synchronized (queues) {
>           ....
>       }
>   }
> {code}
> Another thread FairScheduler.assignToQueue may also need to create a new queue when a
new job submitted. This thread would hold the *QueueManager's queues lock* firstly, and then
would like to hold the *FairScheduler's lock* as it needs to call FairScheduler.getClock()
function when creating a new FSLeafQueue. Deadlock may happen here.
> 2. The AllocationFileLoaderService holds  *AllocationFileLoaderService's lock* first,
and then waits for *FairScheduler's lock*. Another thread (like AdminService.refreshQueues)
may call FairScheduler's reinitialize function, which holds *FairScheduler's lock* first,
and then waits for *AllocationFileLoaderService's lock*. Deadlock may happen here.



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

Mime
View raw message