As a core element to provide the HA feature, it is a message exchanged among master, slave, and replica nodes to monitor the status of other nodes. A master process periodically exchanges heartbeat messages with all other master processes in the group. A heartbeat message is exchanged through the UDP port configured in the ha_port_id parameter of cubrid.conf. The exchange interval of heartbeat messages is determined by an internally configured value.
When the master node fails, a failover occurs to a slave node.