[ 
https://issues.apache.org/jira/browse/YARN-3591?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14553981#comment-14553981
 ] 

Lavkesh Lahngir commented on YARN-3591:
---------------------------------------

The code shows that full dirs are both readable and writable. So a resource can 
still be read from the full disk. 
We should just call checkLocalizedResources() on both goodirs and fulldirs. 
Then resources in cache will deleted which are localized on bad disk. 
In addition we can actually try to remove resources from the disk by calling 
remove().
thoughts ?

> Resource Localisation on a bad disk causes subsequent containers failure 
> -------------------------------------------------------------------------
>
>                 Key: YARN-3591
>                 URL: https://issues.apache.org/jira/browse/YARN-3591
>             Project: Hadoop YARN
>          Issue Type: Bug
>    Affects Versions: 2.7.0
>            Reporter: Lavkesh Lahngir
>            Assignee: Lavkesh Lahngir
>         Attachments: 0001-YARN-3591.1.patch, 0001-YARN-3591.patch, 
> YARN-3591.2.patch, YARN-3591.3.patch, YARN-3591.4.patch
>
>
> It happens when a resource is localised on the disk, after localising that 
> disk has gone bad. NM keeps paths for localised resources in memory.  At the 
> time of resource request isResourcePresent(rsrc) will be called which calls 
> file.exists() on the localised path.
> In some cases when disk has gone bad, inodes are stilled cached and 
> file.exists() returns true. But at the time of reading, file will not open.
> Note: file.exists() actually calls stat64 natively which returns true because 
> it was able to find inode information from the OS.
> A proposal is to call file.list() on the parent path of the resource, which 
> will call open() natively. If the disk is good it should return an array of 
> paths with length at-least 1.



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

Reply via email to