As mentioned earlier in this chapter, YARN defines two schedulers (capacity and fair schedulers). These schedulers use their own implementation of the queue interface. The following diagram represents a class diagram for different queues defined in YARN:
CSQueue
is an interface that extends the Queue
interface. It is defined in the org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity
package. The CSQueue
interface represents a queue structure for a node in the tree of hierarchical queues for CapacityScheduler
.
The two classes that implement the CSQueue
interface are as follows:
ParentQueue
LeafQueue
The properties associated with a CapacityScheduler
queue are as follows:
yarn.scheduler.capacity.<queue-path>.capacity
: This is a float value that specifies the capacity of the queue in percentage (%). At each level of queues (hierarchical queues), the sum of capacities for all queues must be equal to 100. In order to provide...