hadoop-hdfs-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Colin Patrick McCabe (JIRA)" <j...@apache.org>
Subject [jira] [Resolved] (HDFS-3290) Use a better local directory layout for the datanode
Date Fri, 15 Jan 2016 23:08:40 GMT

     [ https://issues.apache.org/jira/browse/HDFS-3290?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel

Colin Patrick McCabe resolved HDFS-3290.
    Resolution: Duplicate

> Use a better local directory layout for the datanode
> ----------------------------------------------------
>                 Key: HDFS-3290
>                 URL: https://issues.apache.org/jira/browse/HDFS-3290
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>    Affects Versions: 0.23.0
>            Reporter: Colin Patrick McCabe
>            Assignee: Colin Patrick McCabe
>            Priority: Minor
> When the HDFS DataNode stores chunks in a local directory, it currently puts all of the
chunk files into either one big directory, or a collection of directories.  However, there
is no way to know which directory a given block will end up in, given its ID.  As the number
of files increases, this does not scale well.
> Similar to the git version control system, HDFS should create a few different top level
directories keyed off of a few bits in the chunk ID.  Git uses 8 bits.  This substantially
cuts down on the number of chunk files in the same directory and gives increased performance,
while not compromising O(1) lookup of chunks.

This message was sent by Atlassian JIRA

View raw message