hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Mingliang Liu (JIRA)" <j...@apache.org>
Subject [jira] [Work started] (HDFS-10335) Mover$Processor#chooseTarget() always chooses the first matching target storage group
Date Wed, 27 Apr 2016 02:14:12 GMT

     [ https://issues.apache.org/jira/browse/HDFS-10335?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Work on HDFS-10335 started by Mingliang Liu.
--------------------------------------------
> Mover$Processor#chooseTarget() always chooses the first matching target storage group
> -------------------------------------------------------------------------------------
>
>                 Key: HDFS-10335
>                 URL: https://issues.apache.org/jira/browse/HDFS-10335
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: balancer & mover
>    Affects Versions: 2.8.0
>            Reporter: Mingliang Liu
>            Assignee: Mingliang Liu
>            Priority: Critical
>
> Currently the {{org.apache.hadoop.hdfs.server.mover.Mover$Processor#chooseTarget()}}
always chooses the first matching target datanode from the candidate list. This may make the
mover schedule a lot of task to a few of the datanodes (first several datanodes of the candidate
list). The overall performance will suffer significantly from this because of the saturated
network/disk usage. Specially, if the {{dfs.datanode.balance.max.concurrent.moves}} is set,
the scheduled move task will be queued on a few of the storage group, regardless of other
available storage groups. We need an algorithm which can distribute the move tasks approximately
even across all the candidate target storage groups.
> Thanks [~szetszwo] for offline discussion.



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

Mime
View raw message