Question-36: What is the Role Group?

Answer: Role group is a set of configuration properties for a set of role instances e.g. NodeManager-1, DataNode-1, Balancer-1 is one set and another set could be NodeManager-HE, DataNode-HE, Balancer-HE. Hence, we can create two Role groups something like that GROUP-1, Group-HE etc. to combine all the configuration properties for the same set of role instances. 

Question-37: What is the use of Gateway node?

Answer: Gateway is again another type of Role, which give access to client for any specific service like accessing HDFS files, Running Hive Queries etc. on the cluster. Sometimes Gateway node are referred as Gateway Node or edge Node. It is mostly the node which is outside of the cluster having access to the Cluster service.

Question-38: What do you mean by Static Service Pool?

Answer: In Cloudera Manager, a static partitioning of total cluster resources e.g. CPU, Memory and I/O weight across a set of services. 

Question-39: What is the role of Cloudera Manager Server?

Answer: Cloudera Manager server is heart of Cloudera Manager. Cloudera Manager Server hosts the

• Web Server for Admin Console
• Application logic
• It is responsible for installing software
• Configuring, Starting & stopping services. 
• Managing the cluster on which the services run. 

Question-40: How does Cloudera Manager able to start and stop services on so many nodes in Hadoop cluster?

Answer: There is an agent which needs to be installed on each host and this agent is responsible for starting and stopping various requested processes. Unpacking the configurations, triggering installations and monitoring the hosts.