Configuring HiveServer high availability
You need to know how to configure your Hive-on-Tez to use ZooKeeper for HiveServer high availability.
When you add one or more additional HiveServer (HS2) role instances to the Hive-on-Tez service, the multiple role instances can register themselves with ZooKeeper. The JDBC client (client driver) can find a HiveServer through ZooKeeper. Using Beeline, you connect to Hive, and the ZooKeeper discovery mechnism locates and connects to one of the running HiveServer instances.
If more than one HiveServer instance is registered with ZooKeeper, and all instances fail except one, ZooKeeper passes the link to the instance that is running and the client can connect successfully. Failed instances must be restarted manually.
Automatic failover does not occur. If an HS2 instance failed while a client is connected, the session is lost. Since this situation needs to be handed at the client, there is no automatic failover; the client needs to reconnect using ZooKeeper.