Configure a custom LLAP queue

As an advanced user, you can create and customize a queue for interactive querying instead of accepting the default llap queue during LLAP setup in Ambari. Using custom queues gives you the flexibility to assign different priorities, or other configurations, to queries run on certain queues, for example.

1. In Ambari, access the capacity scheduler:
   • Select YARN > Configs > Advanced, and in Filter enter yarn.scheduler.capacity.root.
   • On the command line of the node where YARN is installed, go to the YARN /conf file, and open the capacity-scheduler.xml file.
2. Define the custom LLAP queue, specifying a name and other properties, such as capacity and usage limits.
   For example:

   yarn.scheduler.capacity.root.queues=myllap
   yarn.scheduler.capacity.root.myllap=50 
   yarn.scheduler.capacity.root.myllap.maximum-capacity=50
   yarn.scheduler.capacity.root.myllap.user-limit=1 

3. From the Ambari dashboard, select ADMIN > Manage Ambari > Views.

   

4. Click the URL for the view named AUTO_CS_INSTANCE, which is the capacity scheduler view.
   
5. In the YARN Queue Manager, click Add Queue.

   

6. Enter the queue path, which is the name of the custom queue myllap hive1.
7. In Ambari, select Services > Hive > Configs > Settings.
8. In Interactive Query, set Enable Interactive Query to Yes:

   

9. In Select HiveServer Interactive Host, select the server to host HiveServer Interactive.
   For example, select the default highlighted server, which is typically a good choice.

   

10. In Interactive Query Queue, select the custom YARN queue to replace the default llap:

    

    This action dedicates all the LLAP daemons and YARN ApplicationMasters of the system to the single, specified queue.