Uploaded image for project: 'IMPALA'
  1. IMPALA
  2. IMPALA-8804

Memory based admission control is always disabled if pool max mem is not set

    XMLWordPrintableJSON

    Details

    • Type: Improvement
    • Status: Open
    • Priority: Major
    • Resolution: Unresolved
    • Affects Version/s: Impala 3.1.0, Impala 3.2.0, Impala 3.3.0
    • Fix Version/s: None
    • Component/s: Backend

      Description

      Memory-based admission control doesn't kick in with the provided config files where no max memory is configured for the pool. This is the documented behaviour and not a bug - see https://impala.apache.org/docs/build/html/topics/impala_admission.html. However, it is inconvenient since you need to specify some max memory value even if you don't want to limit the pool's share of the clusters resources (or the cluster is variable in size).

      This is unfriendly. It is also confusing since there is no explicit way to enable memory-based admission control.

      You can workaround by setting the pool max memory to a very high value.

      To reproduce, start a minicluster with the provided configs. If you submit multiple memory-intensive queries in parallel, they will never be queued.

      start-impala-cluster.py --impalad_args="-fair_scheduler_allocation_path=minicluster-fair-scheduler.xml -llama_site_path=minicluster-llama-site.xml" --impalad_args=-vmodule=admission-controller
      

        Attachments

        1. minicluster-llama-site.xml
          0.8 kB
          Tim Armstrong
        2. minicluster-fair-scheduler.xml
          1 kB
          Tim Armstrong

          Activity

            People

            • Assignee:
              asherman Andrew Sherman
              Reporter:
              tarmstrong Tim Armstrong
            • Votes:
              0 Vote for this issue
              Watchers:
              2 Start watching this issue

              Dates

              • Created:
                Updated: