[jira] [Updated] (HDFS-5754) Split LayoutVerion into NamenodeLayoutVersion and DatanodeLayoutVersion

["Brandon Li (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HDFS-5754?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Brandon Li updated HDFS-5754:
-----------------------------

    Attachment: HDFS-5754.001.patch

Uploaded the initial patch. It added a datanode layout version and removed namenode version check during datanode registration. 

> Split LayoutVerion into NamenodeLayoutVersion and DatanodeLayoutVersion 
> ------------------------------------------------------------------------
>
>                 Key: HDFS-5754
>                 URL: https://issues.apache.org/jira/browse/HDFS-5754
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>          Components: datanode, namenode
>            Reporter: Tsz Wo (Nicholas), SZE
>            Assignee: Brandon Li
>         Attachments: HDFS-5754.001.patch
>
>
> Currently, LayoutVersion defines the on-disk data format and supported features of the entire cluster including NN and DNs.  LayoutVersion is persisted in both NN and DNs.  When a NN/DN starts up, it checks its supported LayoutVersion against the on-disk LayoutVersion.  Also, a DN with a different LayoutVersion than NN cannot register with the NN.
> We propose to split LayoutVersion into two independent values that are local to the nodes:
> - NamenodeLayoutVersion - defines the on-disk data format in NN, including the format of FSImage, editlog and the directory structure.
> - DatanodeLayoutVersion - defines the on-disk data format in DN, including the format of block data file, metadata file, block pool layout, and the directory structure.  
> The LayoutVersion check will be removed in DN registration.  If NamenodeLayoutVersion or DatanodeLayoutVersion is changed in a rolling upgrade, then only rollback is supported and downgrade is not.



--
This message was sent by Atlassian JIRA
(v6.1.5#6160)