[
https://issues.apache.org/jira/browse/HDFS-2832?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13192326#comment-13192326
]
Suresh Srinivas commented on HDFS-2832:
---------------------------------------
Advantages:
# Support for heterogeneous storages:
#* DN could support along with disks, other types of storage such as flash etc.
#* Suitable storage can be chosen based on client preference such as need for
random reads etc.
# Block report scaling: instead of a single monolithic block report, a smaller
block report per storage becomes possible. This is important with the growth in
disk capacity and number of disks per datanode.
# Better granularity of storage failure handling:
#* DN could just indicate loss of storage and namenode can handle it better
since it knows the list of blocks belonging to a storage.
#* DN could locally handle storage failures or provide decommissioning of a
storage by marking a storage as ReadOnly.
# Hot pluggability of disks/storages: adding and deleting a storage to a node
is simplified.
# Other flexibility: includes future enhancements to balance storages with in a
datanode, balancing the load (number of transceivers) per storage etc and
better block placement strategies.
Backward compatibility:
The existing grouping of all storages under a single storage ID is a specific
case of the generalized model proposed above. This change will be backward
compatible with the existing deployments.
> Enable support for heterogeneous storages in HDFS
> -------------------------------------------------
>
> Key: HDFS-2832
> URL: https://issues.apache.org/jira/browse/HDFS-2832
> Project: Hadoop HDFS
> Issue Type: New Feature
> Affects Versions: 0.24.0
> Reporter: Suresh Srinivas
> Assignee: Suresh Srinivas
>
> HDFS currently supports configuration where storages are a list of
> directories. Typically each of these directories correspond to a volume with
> its own file system. All these directories are homogeneous and therefore
> identified as a single storage at the namenode. I propose, change to the
> current model where Datanode * is a * storage, to Datanode * is a collection
> * of strorages.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
