I am going through the concepts of resource manager, application master and node manager. As I undersand resource manager receives the job submission and launches application master. It also launches node manager to monitor application master. My questions are:
1. Is Node manager long lived and that one node manager monitors all the containers launed on the data nodes? 2. How is resource negotiation done between the application master and the resource manager? In other words what happens during this step? Does resource manager looks at the active and pending tasks and resources consumed by those before giving containers to the application master? 3. As it happens in old map reduce cluster that task trackers sends periodic heartbeats to the job tracker nodes. How does this compare to YARN? It looks like application master is a task tracker? Little confused here. 4. It looks like client polls application master to get the progress of the job but initially client connects to the resource manager. How does client gets reference to the application master? Does it mean that client gets the node ip/port from resource manager where application master was launced by the resource manager?
