HBase Architectural Components

Regions

HBase tables are divided horizontally by row key range into Regions, thus a Region contains all rows in the table between the region’s start key and end key.

Regions are assigned to the nodes in the cluster, called Region Servers. These servers serve data for read and write.

HMaster

HMaster handles region management and Data Definition Language operation (create, delete, update tables).

Region management means assigning regions for recovery or load balancing, and monitoring all servers.