Enable System Service Mode

When you upgrade an HDP cluster from 2.6.x to 3.0, the upgraded YARN service includes HBase installed in the embedded mode. If your cluster meets the capacity requirements for the HBase component associated with Timeline Service 2.0 to run as a separate ats-hbase service, you must enable the system service mode.

1. Configure a separate queue at the root level, say yarn system, for the ats-hbase service instead of using the default queue.
2. Allocate required resources to the yarn-system queue for launching the ats-hbase service.
   The minimum amount of memory required for launching ats-hbase is 12 GB.
   To allocate resources, update the value of the yarn.scheduler.capacity.root.<queue_path>.capacity property in capacity-scheduler.xml. The following is an example:

   yarn.scheduler.capacity.root.yarn-system.capacity=10

3. Set ACLs on the yarn-system queue such that the yarn-ats user can manage the ats-hbase service.
   To set ACLs on the queue, update values of the yarn.scheduler.capacity.root.<queue-path>.acl_submit_applications and yarn.scheduler.capacity.root.<queue-path>.acl_administer_queue in capacity-scheduler.xml.

   yarn.scheduler.capacity.root.yarn-system.acl_submit_applications=yarn-ats,yarn
   yarn.scheduler.capacity.root.yarn-system.acl_administer_queue=yarn-ats,yarn

4. Disable preemption on the yarn-system queue.
   Set yarn.scheduler.capacity.root.<queue-path>.disable_preemption and yarn.scheduler.capacity.root.<queue-path>.intra-queue-preemption.disable_preemption in capacity-scheduler.xml to true.

   yarn.scheduler.capacity.root.yarn-system.disable_preemption=true
   yarn.scheduler.capacity.root.yarn-system.intra-queue-preemption.disable_preemption=true

5. Assign the highest priority to the yarn-system queue to prevent inadvertent deletion or preemption.
   Set the value of yarn.scheduler.capacity.root.<queue-path>.priority in capacity-scheduler.xml.

   yarn.scheduler.capacity.root.yarn-system.priority=<maximum-integer-value>

6. Enable the is_hbase_system_service_launch property in yarn-hbase.env.
7. Restart YARN.