In a simple setup, there are two master nodes and multiple slave nodes:
Master A) NameNode service, Hive Master
Master B) JobTracker (HDP-1) or ResourceManager (HDP-2), HBase RegionServer
Slaves
On master nodes: Configured for reliability (Raid 10, dual ethernet cards, dual power supplies, etc.)
On slave nodes: Raid is not necessary as failure on these nodes is managed automatically by the cluster. All data is stored across at least three different host and redundancy is built in. Slave nodes should be built for speed and low cost.
