[Hadoop-common-dev] [jira] Created: (HADOOP-2266) Provide a command line option to check if a Hadoop jobtracker is idle

[ https://issues.apache.org/jira/browse/HADOOP-2266?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Hemanth Yamijala updated HADOOP-2266:
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Fix Version/s: 0.16.0

[ https://issues.apache.org/jira/browse/HADOOP-2266?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12545237 ]

Owen O'Malley commented on HADOOP-2266:
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Another approach to this would be to have an admin command for the job tracker that would have the job tracker stop accepting new jobs and shut itself down when the last job completed. That way the external process wouldn't need to continually poll the job tracker to see if it was done yet. Thoughts?

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Enis Soztutar commented on HADOOP-2266:
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bq. Another approach to this would be to have an admin command for the job tracker that would have the job tracker stop accepting new jobs and shut itself down when the last job completed.
I remember this was discussed before but never implemented. I think this and a command to gracefully stop the jt would be great.

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Michael Bieniosek commented on HADOOP-2266:
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It's possible to do this through the JobClient API currently.

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Hemanth Yamijala commented on HADOOP-2266:
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bq. Another approach to this would be to have an admin command for the job tracker that would have the job tracker stop accepting new jobs and shut itself down when the last job completed. That way the external process wouldn't need to continually poll the job tracker to see if it was done yet. Thoughts?

The requirement we have in Hadoop On Demand is to shutdown a job tracker when it has not run any jobs for a period of time. This is to help in releasing unused resources, and reclaim them. The approach suggested above actually makes sense if we want to run the job tracker for a period of time and then shutdown. This seems to be different from what we need, right ?

The problem of continous polling does exist. But I feel it may not be too intensive. Any alternative that does not have this problem, but solves the use-case would also be great.

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Arun C Murthy commented on HADOOP-2266:
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The other other issue is see with the JT shutting itself down is that the TTs (and HoD) don't know why that happened. If we just implement the *isidle <for_this_long>*, we could let HoD make the decision to shut down the entire cluster via the usual scripts... thoughts?

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Arun C Murthy commented on HADOOP-2266:
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Let me clarify, I agree 'graceful shutdown' initiated by the JT is the _right_ solution.

However, the command, as described here, is a good interim solution IMHO.