In YARN client mode, the Driver runs on a node outside the cluster (typically where the client is). Driver first contacts the resource manager requesting resources to run the Spark job. The resource manager allocates a container (container zero) and responds to the Driver. The Driver then launches the Spark application master in the container zero. The Spark application master then creates the executors on the containers allocated by the resource manager. The YARN containers can be on any node in the cluster controlled by node manager. So, all allocations are managed by resource manager.