Enable asynchronous scheduler

Asynchronous scheduler decouples the CapacityScheduler scheduling from Node Heartbeats. This improves the latency significantly.

To enables asynchronous scheduling (yarn.scheduler.capacity.schedule-asynchronously.enable), perform the following:

1. In Cloudera Manager, select Clusters > YARN Queue Manager UI service. A graphical queue hierarchy is displayed in the Overview tab.
2. Click on the Scheduler Configuration tab.
3. Select the Enable Asynchronous Scheduler check-box.
4. Click Save.