Embedded Yarn minicluster for testcases that need to interact with a cluster.
In a real cluster, resource request matching is done using the hostname, and by default Yarn minicluster works in the exact same way as a real cluster.
If a testcase needs to use multiple nodes and exercise resource request matching to a specific node, then the property {@YarnConfiguration.RM_SCHEDULER_INCLUDE_PORT_IN_NODE_NAME} should be set
true in the configuration used to initialize the minicluster.
With this property set to
true, the matching will be done using the
hostname:port of the namenodes. In such case, the AM must do resource request using
hostname:port as the location.