Question-31: Can you use virtual machine as a host in the Cloudera Manager?
Answer: Yes, in Cloudera Manager you can have either Physical or virtual machine as a host which runs the role instances. A host can belong to only one cluster.
Question-32: Can you tell me something about Rack?
Answer: Rack is a physical entity which contains a set of physical hosts typically served by the same switch.
Question-33: What do you mean by service or service type, with respect to Cloudera Manager?
Answer: In case of Cloudera Manager, you can say it is a category with the managed functionality which may or may not be distributed. Which is referred as either Service or service type. For example, MapReduce, HDFS, YARN, Spark, Accumulo etc. It is possible that same single service can run on more than one host.
Question-34: What is service instance?
Answer: You would be creating an instance from a service like HDFS is one service, you would be creating its instance by giving some name like “HDFS-HE” or “HDFS-A” etc. It is possible that a single service instance span across multiple Role instances.
Question-35: What do you mean by a Role in a service?
Answer: As you know a single service can have various functionality like HDFS has below functionality
- NameNode
- Secondary NameNode
- DataNode
- Balancer
Hence, role represent any of this functionality, sometimes this is also referred as Role Type. And similarly, for each role you would be creating a role instance. Each Role instance equivalent to a Unix process. For example, running a NodeManager instance.
