hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Doug Cutting (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-1804) Modify or add a new block-volume device choosing policy that looks at free space
Date Fri, 15 Apr 2011 17:35:05 GMT

    [ https://issues.apache.org/jira/browse/HDFS-1804?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13020367#comment-13020367
] 

Doug Cutting commented on HDFS-1804:
------------------------------------

Dhruba, I meant biased by available free space.  Randomly biased by free space would, as Todd
suggests, not spread load as evenly between devices as would round-robin.  So, if disk A has
twice the free space of disks B and C then allocations should ideally go {A,B,A,C,A,B,A,C...}
rather than a stateless probabilistic allocation which would often send repeated allocations
to A, impacting throughput.

> Modify or add a new block-volume device choosing policy that looks at free space
> --------------------------------------------------------------------------------
>
>                 Key: HDFS-1804
>                 URL: https://issues.apache.org/jira/browse/HDFS-1804
>             Project: Hadoop HDFS
>          Issue Type: New Feature
>          Components: data-node
>            Reporter: Harsh J Chouraria
>            Priority: Minor
>             Fix For: 0.23.0
>
>
> HDFS-1120 introduced pluggable block-volume choosing policies, but still carries the
vanilla RoundRobin as its default.
> An additional implementation that also takes into consideration the free space remaining
on the disk (or other params) should be a good addition as an alternative to vanilla RR.

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message