Apache Hive Performance Tuning
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Configure an llap queue

Ambari generally creates and configures an interactive query queue named llap and points the Hive service to a YARN queue. You check, and if necessary, change the llap queue using YARN Queue Manager.

The llap queue capacity determines the YARN resources for the LLAP application. Reconfiguring the llap queue is sometimes necessary. For example, if you have a 3-node cluster, Ambari might configure zero percent capacity for the llap queue, and you must reconfigure settings. If you set the llap queue capacity or number of nodes too low, you won’t have enough YARN resources or LLAP daemons to run the LLAP application. If you set the llap queue capacity too high, you waste space on the cluster.

  1. In Ambari, select Hive > Configs.
  2. In Interactive Query Queue, choose the llap queue if it appears as a selection:
    Depending on your YARN Capacity Scheduler settings, a queue named llap might or might not appear. This setting dedicates all LLAP daemons and all YARN Application Masters (AMs) of the system to the single, specified queue.
  3. In Ambari, from Views, select Services > YARN > YARN Queue Manager from the hamburger menu icon.
  4. If an llap queue does not exist, add a queue named llap. Otherwise, proceed to the next step.
  5. If the llap queue is stopped, change the state to running.
  6. Check the llap queue capacity, and accept or change the value as follows:
    • If the llap queue capacity is zero, you might have too few nodes for Ambari to configure llap queue capacity. Go to the next step to configure llap queue capacity and max capacity.
    • If Ambari set the llap capacity to greater than zero, no change is necessary. Skip the next step. For example, in a 7-node cluster, Ambari allocates llap queue capacity as follows:
  7. If llap queue capacity is zero, increase the capacity allocated to your llap queue, and also change max capacity to the remainder of the allocated llap capacity minus 100 percent.

    For example, set max capacity to 100 percent minus 50 percent = 50 percent.

    Allocating 15-50 percent of cluster to the llap queue is common.

  8. Select the llap queue under Add Queue, and in Resources that appears on the right, set User Limit Factor to 1, and set Priority to greater than 0 (1 for example).
  9. Select Actions > Save and Refresh Queues.
  10. In Services > YARN > Summary restart any YARN services as prompted.