A, YARN basic cluster architecture
Second, the functions of the respective components
ResourceManager：
Global Explorer, the entire cluster is only one responsible for unified management and scheduling of resources allocated cluster.
Function:
processing client requests
start / monitoring Application Master
Monitor NodeManager
resource allocation and scheduling
NodeManager：
More than the entire cluster, responsible for resource management and use of a single node.
Function:
resource management and task management (monitoring Container resource usage, not monitoring tasks) on a single node
to the ResourceManager report
processing Application Master Command
Task：
Specific tasks of the application
Container：
In the basic unit of resource allocation YARN, sealed the CPU and
a memory container resources, the equivalent of a Task abstract operating environment.
Container required a program is divided into two types: ApplicationManager run and run all kinds of Task. The former is similar to the computer resources needed for the entire program, which is to be ResourceManager Resources
Function:
abstract task operating environment
described a series of information
tasks run the resource (node, memory, cpu)
task start command
Application Master：
Application Administrator, responsible for managing a single application (cluster may have multiple applications running, each application has its own Application Master)
Function:
for the application to apply the resources (CPU, memory) to ResourseManager
the Task allocate resources to manage applications
running start and monitor the status of Task run progress and
shut down and release their Container
