[ 
https://issues.apache.org/jira/browse/HDFS-9422?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15007962#comment-15007962
 ] 

Walter Su commented on HDFS-9422:
---------------------------------

I have no idea why use Arrays.sort() instead of Collections.sort(). And why 
sort() need to be synchronized. I think it makes sense to remove the lock.

> Unnecessary FsDatasetImpl locking in DirectoryScanner cause periodic datanode 
> pauses
> ------------------------------------------------------------------------------------
>
>                 Key: HDFS-9422
>                 URL: https://issues.apache.org/jira/browse/HDFS-9422
>             Project: Hadoop HDFS
>          Issue Type: Bug
>            Reporter: He Liangliang
>            Assignee: He Liangliang
>         Attachments: HDFS-9422.patch
>
>
> In DirectoryScanner, the scan call hold the global dataset lock for quite 
> long time (typically > 5 secs for 500k blocks). This will stuck the client 
> which need acquire this lock. For applications like HBase, this will affect 
> the latency. In fact, this lock is unnecessary.



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

Reply via email to