[
https://issues.apache.org/jira/browse/HDFS-5754?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Brandon Li updated HDFS-5754:
-----------------------------
Attachment: HDFS-5754.006.patch
Currently there is one LayoutVersion instance per NameNode process. After we
split it into NameNode LayoutVersion and DataNode LayoutVersion, we will have
one instance in NameNode, and one instance in DataNode.
This could be a problem for unit tests since MiniDFSCluster has both NameNode
and DataNode as threads.
Therefore, I've added a static LayoutVersion variable in both NameNode and
DataNode to make sure that MiniDFSCluster won't have problem running unit tests
later on.
I've uploaded a new patch. The features before rolling upgrade are duplicated
in both NameNode.Feature and DataNode.Feature just to simplify the code change.
I can keep the common features in LayoutVersion class if it's preferred.
> 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, HDFS-5754.002.patch,
> HDFS-5754.003.patch, HDFS-5754.004.patch, HDFS-5754.006.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)
