[
https://issues.apache.org/jira/browse/HDFS-2185?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13246045#comment-13246045
]
Todd Lipcon commented on HDFS-2185:
-----------------------------------
bq. I think you are missing the failure arc when transitionToStandby is called
in InElection state.
This failure handling isn't necessary, since any failure to transition will be
shortly followed by the health monitor entering a bad state. This is because a
failure in state transition causes the NN to abort.
bq. Is there any scope for admin operations in ZKFC. Will ZKFC receive and
accept a signal (manual admin/auto machine reboot) to stop services? At that
point, in InElection state, how will it know that it needs to send
transitionToStandby or not (based on whether it is active or not)?
I just added a section regarding manual failover operation in conjunction with
automatic. I was hoping we could merge the automatic work back to trunk prior
to adding this feature, though, treating it as an improvement.
> HA: HDFS portion of ZK-based FailoverController
> -----------------------------------------------
>
> Key: HDFS-2185
> URL: https://issues.apache.org/jira/browse/HDFS-2185
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: auto-failover, ha
> Affects Versions: 0.24.0, 0.23.3
> Reporter: Eli Collins
> Assignee: Todd Lipcon
> Fix For: Auto failover (HDFS-3042)
>
> Attachments: Failover_Controller.jpg, hdfs-2185.txt, hdfs-2185.txt,
> hdfs-2185.txt, hdfs-2185.txt, hdfs-2185.txt, zkfc-design.pdf,
> zkfc-design.pdf, zkfc-design.pdf, zkfc-design.pdf, zkfc-design.tex
>
>
> This jira is for a ZK-based FailoverController daemon. The FailoverController
> is a separate daemon from the NN that does the following:
> * Initiates leader election (via ZK) when necessary
> * Performs health monitoring (aka failure detection)
> * Performs fail-over (standby to active and active to standby transitions)
> * Heartbeats to ensure the liveness
> It should have the same/similar interface as the Linux HA RM to aid
> pluggability.
--
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
