What if node Manager fails?
If any health check fails, the NodeManager marks the node as unhealthy and communicates this to the ResourceManager, which then stops assigning containers to the node. Communication of the node status is done as part of the heartbeat between the NodeManager and the ResourceManager.
What is the main role of resource manager in YARN?
As previously described, ResourceManager (RM) is the master that arbitrates all the available cluster resources and thus helps manage the distributed applications running on the YARN system. It works together with the per-node NodeManagers (NMs) and the per-application ApplicationMasters (AMs).
What is hive used as?
Hive allows users to read, write, and manage petabytes of data using SQL. Hive is built on top of Apache Hadoop, which is an open-source framework used to efficiently store and process large datasets. As a result, Hive is closely integrated with Hadoop, and is designed to work quickly on petabytes of data.
How are failures detected in yarn?
An application master sends periodic heartbeats to the resource manager, and in the event of application master failure, the resource manager will detect the failure and start a new instance of the master running in a new container (managed by a node manager).
How do I stop yarn NodeManager?
- Execute this command on all NodeManagers: su -l yarn -c “/usr/hdp/current/hadoop-yarn-nodemanager/sbin/yarn-daemon.sh stop nodemanager”
- Execute this command on the History Server host machine: su -l mapred -c “/usr/hdp/current/hadoop-mapreduce-historyserver/sbin/mr-jobhistory-daemon.sh stop historyserver”