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https://issues.apache.org/jira/browse/MAPREDUCE-4328?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13439804#comment-13439804
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Arun C Murthy commented on MAPREDUCE-4328:
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Ah, I thought I responded to ATM, my bad.
As I've described in the description of the jira the primary use-case is to
allow JobTracker to be resilient to NN failures (hardware or software).
I did think long and hard about doing this in YARN, but with HDFS-HA this
use-case is pretty much non-existent. Furthermore, since YARN isn't tied to
HDFS as MR1 is; and since it's distributed across several AMs there is no
single point of control like the JT in MR1. Thus, I think there isn't enough
value in porting it as-is, conceptually (not code-wise).
In many ways this is similar to MAPREDUCE-3837, i.e. no straight-backport.
Having said that, I plan to make sure we pay attention to this when we get
around to fixing RM Restart. This is something I definitely plan to do later
this year, at which point we'll ensure there is no 'feature regression'.
Makes sense?
----
Eli's point about draining queues is a good one, I've opened MAPREDUCE-4575 and
YARN-38 to track that. That feature is something we can do a straight-mapping
conceptually across MR1 and YARN.
> Add the option to quiesce the JobTracker
> ----------------------------------------
>
> Key: MAPREDUCE-4328
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-4328
> Project: Hadoop Map/Reduce
> Issue Type: Improvement
> Components: mrv1
> Affects Versions: 1.0.3
> Reporter: Arun C Murthy
> Assignee: Arun C Murthy
> Fix For: 1.2.0
>
> Attachments: MAPREDUCE-4328.patch, MAPREDUCE-4328.patch,
> TestJobTrackerQuiescence.java
>
>
> In several failure scenarios it would be very handy to have an option to
> quiesce the JobTracker.
> Recently, we saw a case where the NameNode had to be rebooted at a customer
> due to a random hardware failure - in such a case it would have been nice to
> not lose jobs by quiescing the JobTracker.
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