[
https://issues.apache.org/jira/browse/HDFS-5535?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13912525#comment-13912525
]
Kihwal Lee commented on HDFS-5535:
----------------------------------
[~stack]: If the local DN was added to {{deadNodes}} in a {{DFSInputStream}}
because it was restarted, we may be able to (asynchronously?) probe and remove
it from {{deadNodes}}. Then when a block boundary is crossed, the local node
will get used again. If explicit restart notifications are complex or
unreliable (due to timing & network, etc), we could do the recovery solely
based on the failure mode. E.g. abrupt connection breakage by the remote end,
connection refusal/reset, etc. Background ping thread can reintroduce it
independent of on-going reads. I haven't checked how easy it is to track the
cause of failures, so I can't say it is feasible just yet.
> Umbrella jira for improved HDFS rolling upgrades
> ------------------------------------------------
>
> Key: HDFS-5535
> URL: https://issues.apache.org/jira/browse/HDFS-5535
> Project: Hadoop HDFS
> Issue Type: New Feature
> Components: datanode, ha, hdfs-client, namenode
> Affects Versions: 3.0.0, 2.2.0
> Reporter: Nathan Roberts
> Attachments: HDFSRollingUpgradesHighLevelDesign.pdf,
> h5535_20140219.patch, h5535_20140220-1554.patch, h5535_20140220b.patch,
> h5535_20140221-2031.patch, h5535_20140224-1931.patch,
> h5535_20140225-1225.patch
>
>
> In order to roll a new HDFS release through a large cluster quickly and
> safely, a few enhancements are needed in HDFS. An initial High level design
> document will be attached to this jira, and sub-jiras will itemize the
> individual tasks.
--
This message was sent by Atlassian JIRA
(v6.1.5#6160)
