As you create the architecture of your cluster, you will need to allocate Cloudera Manager and Runtime roles among the hosts in the cluster to maximize your use of resources. Cloudera provides some guidelines about how to assign roles to cluster hosts. See Recommended Cluster Hosts and Role Distribution. When multiple roles are assigned to hosts, add together the total resource requirements (memory, CPUs, disk) for each role on a host to determine the required hardware.
For more information about sizing for a particular component, see the following minimum requirements: