[ 
https://issues.apache.org/jira/browse/HDFS-12809?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16261836#comment-16261836
 ] 

Virajith Jalaparti commented on HDFS-12809:
-------------------------------------------

[~elgoiri], wrt your 
[comment|https://issues.apache.org/jira/browse/HDFS-12778?focusedCommentId=16255428&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-16255428]
 on HDFS-12778, I filed HDFS-12848. This JIRA is to just fix the random 
selection policy that is currently implemented. We can make it pluggable later 
on.

> [READ] Fix the randomized selection of locations in {{ProvidedBlocksBuilder}}.
> ------------------------------------------------------------------------------
>
>                 Key: HDFS-12809
>                 URL: https://issues.apache.org/jira/browse/HDFS-12809
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>            Reporter: Virajith Jalaparti
>            Assignee: Virajith Jalaparti
>         Attachments: HDFS-12809-HDFS-9806.001.patch
>
>
> Calling {{getBlockLocations}} on files that have a PROVIDED replica, results 
> in the datanode locations being selected at random. Currently, this 
> randomization uses the datanode uuids to pick a node at random 
> ({{ProvidedDescriptor#choose}}, {{ProvidedDescriptor#chooseRandom}}). 
> Depending on the distribution of the datanode UUIDs, this can lead to large 
> number of iterations (which may not terminate) before a location is chosen. 
> This JIRA aims to replace this with a more efficient randomization strategy.



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

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

Reply via email to