[
https://issues.apache.org/jira/browse/HDFS-4796?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Ted Yu resolved HDFS-4796.
--------------------------
Resolution: Won't Fix
> Port HDFS-4721 'Speed up lease/block recovery when DN fails and a block goes
> into recovery' to branch 1
> -------------------------------------------------------------------------------------------------------
>
> Key: HDFS-4796
> URL: https://issues.apache.org/jira/browse/HDFS-4796
> Project: Hadoop HDFS
> Issue Type: Improvement
> Reporter: Ted Yu
>
> This was observed while doing HBase WAL recovery. HBase uses append to write
> to its write ahead log. So initially the pipeline is setup as
> DN1 --> DN2 --> DN3
> This WAL needs to be read when DN1 fails since it houses the HBase
> regionserver for the WAL.
> HBase first recovers the lease on the WAL file. During recovery, we choose
> DN1 as the primary DN to do the recovery even though DN1 has failed and is
> not heartbeating any more.
> To speedup lease/block recovery, we always choose the datanode with the most
> recent heartbeat.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
