Identify the MapReduce v2 (MRv2 / YARN) daemon responsible for launching application
containers and monitoring application resource usage?
A.
ResourceManager
B.
NodeManager
C.
ApplicationMaster
D.
ApplicationMasterService
E.
TaskTracker
F.
JobTracker
Explanation:
The fundamental idea of MRv2 (YARN) is to split up the two major functionalities of
the JobTracker, resource management and job scheduling/monitoring, into separate daemons.
The idea is to have a global ResourceManager (RM) and per-application ApplicationMaster (AM).
An application is either a single job in the classical sense of Map-Reduce jobs or a DAG of jobs.
Note: Let’s walk through an application execution sequence :
Reference: Apache Hadoop YARN – Concepts & Applications
Ans:B-Nodemanager
0
0
Answer is B:
The YARN node managers, which launch and monitor the compute containers on
machines in the cluster.
Hadoop the define guide Page 198
0
0
c
0
0
C
It is the Application Master which monitors application resource usage. NodeManager keeps track of the entire Node resource usage , but not at application level.
0
0
B
Nodemanager is launching the containers themselves. The container can be an ApplicationMaster or a child. AM is only asking other nodes’ Nodemanager to launch the taskattempts, but it e.g. cannot directly monitor their resource usage.
http://image.slidesharecdn.com/04-mapred-6-jobexecutiononyarn-130330082800-phpapp02/95/hadoop-tutorial-mapreduce-part-6-job-execution-on-yarn-8-638.jpg
0
0
B. Technically AM is not a daemon but just another user process.
0
0