HBase working mechanism

1,hbase Regionserver Register with zookeeper to provide hbase regionserver status information (online)
2,hmaster The HBase system table-root-is loaded into zookeeper cluster at boot time, and the current system table can be obtained through zookeeper cluster. META. The regionserver information corresponding to the store.
The main function of Hmaster is to maintain the system table-root by Hmaster-,. META., records the region change information for Regionserver. It is also responsible for monitoring Regionserver status change information in the current HBase cluster.
HBase Regionserver is used for multiple/individual maintenance region.
Region corresponds to the table partition data maintenance for the HBase data table.

Simply put: Zookeeper is the scheduler for HBase, and all client access first gets a session from zookeeper
ZK is also responsible for monitoring the health status of all region servers ~ ~
If ZK monitors a region SERVER every three minutes (configurable), ZK notifies Hmaster,hmaster to pull up the hanging RS if it finds a certain RS is hung up.