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YARN Forum

Yarn JMX QueueMetrics "q=root" vs "q=root,q1=default"

  • #58533
    Hari Sekhon

    In the Resource Manager’s JMX can anyone explain to me the difference between Hadoop:service=ResourceManager,name=QueueMetrics “q0=root,q1=default” and “q0=root”?

    I’ve noticed most of the metrics are the same, but q0=root always shows active users 0, while “q0=root,q1=default” shows a positive integer as expected for active users when queries are running in Hive/Tez.

  • Author
  • #58589
    Hari Sekhon

    Ok I went back over the docs, it’s hierarchical of course, but I’m surprised that active users are only counted in leaf queues when I would have expected the top level queue to contain the aggregate summary information for all child queues including the number of active users.

    Can anyone explain this behaviour? Is this something that needs to be fixed so that ‘root’ shows the number of active users in all sub-queues?

    Aneesh Karunakaran

    in your case, q0 is the ‘root queue’ and q1 is the leaf queue. Jobs are allowed to run only on leaf nodes.

    You can read more details about capacity scheduler here –

    Hari Sekhon

    I’ve read the docs on it – more than once (you forget after you don’t tune your queues for a few months…)

    I still think the root level should provide aggregate summary statistics for the leaf levels.

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