1. Architecture roles
1）Region Server
Region Server is the manager of Region, and its implementation class is HRegionServer . Its main functions are as follows: For data operations: get, put, delete; for Region operations: splitRegion, compactRegion.
2）Master
Master is the manager of all Region Servers. Its implementation class is HMaster. Its main functions are as follows: For table operations: create, delete, alter; for RegionServer operations: assign regions to each RegionServer, monitor the status of each RegionServer, load Balancing and failover.
3）Zookeeper
HBase uses Zookeeper to perform tasks such as high availability of the Master, monitoring of the RegionServer, entry of metadata, and maintenance of the cluster configuration.
4）HDFS
HDFS provides the ultimate underlying data storage service for HBase, and at the same time provides high availability support for HBase.
2. Column family and store relationship
Column family and store have a one-to-many relationship, because the table will be split up and down, and the same column family will be split into multiple. Multiple stores corresponding to the same column family are in different Regions, because different stores in the same Region generate different storefiles, and the contents generated by different column families are placed in different folders.