Planning the Cluster
A MapR Hadoop installation is usually a large-scale set of individual servers, called nodes, collectively called a cluster. In a typical cluster, most nodes are dedicated to data processing and storage, and a smaller number of nodes run other services that provide cluster coordination and management.
The first step in deploying MapR is planning which servers will form the cluster, and selecting the services that will run on each node. To determine whether a server is capable of contributing to the cluster, it may be necessary to check the requirements in Preparing Each Node. Each node in the cluster must be carefully checked against these requirements; unsuitability of a node is one of the most common reasons for installation failure.
The objective of a cluster plan is to detail each node's set of services.