[ 
https://issues.apache.org/jira/browse/HDFS-14440?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16829712#comment-16829712
 ] 

Íñigo Goiri commented on HDFS-14440:
------------------------------------

Before the patch, we had the list of remote locations say A, B, C, and D.
Then we checked the first one that had the file, say B.
But now the HashMap can come with A, C, D, B.
If the file is in C and B, we would use C now.

> RBF: Optimize the file write process in case of multiple destinations.
> ----------------------------------------------------------------------
>
>                 Key: HDFS-14440
>                 URL: https://issues.apache.org/jira/browse/HDFS-14440
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>            Reporter: Ayush Saxena
>            Assignee: Ayush Saxena
>            Priority: Major
>         Attachments: HDFS-14440-HDFS-13891-01.patch, 
> HDFS-14440-HDFS-13891-02.patch
>
>
> In case of multiple destinations, We need to check if the file already exists 
> in one of the subclusters for which we use the existing getBlockLocation() 
> API which is by default a sequential Call,
> In an ideal scenario where the file needs to be created each subcluster shall 
> be checked sequentially, this can be done concurrently to save time.
> In another case where the file is found and if the last block is null, we 
> need to do getFileInfo to all the locations to get the location where the 
> file exists. This also can be prevented by use of ConcurrentCall since we 
> shall be having the remoteLocation to where the getBlockLocation returned a 
> non null entry.
>  



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to