High Availability (HA) refers to a feature to provide uninterrupted service in the event of hardware, software, or network failure. This ability is a critical element in the network computing area where services should be provided 24/7. An HA system consists of more than two server systems, each of which provides uninterrupted services, even when a failure occurs in one of them.
CUBRID HA is an implementation of High Availability. The CUBRID HA feature ensures database synchronization among multiple servers when providing service. When an unexpected failure occurs in the system which is operating services, this feature minimizes the service down time by allowing the other system to carry out the service automatically.
The CUBRID HA feature is in a shared-nothing structure. To synchronize data from an active server to a standby server, the CUBRID HA feature executes the following two steps.
The CUBRID HA feature executes the steps described above in order to always maintain data synchronization between an active server and a standby server. For this reason, if an active server is not working properly because of a failure occurring in the master node that had been providing service, the standby server of the slave node provides service instead of the failed server. The CUBRID HA feature monitors the status of the system and CUBRID in real time. It uses heartbeat messages to execute an automatic failover when a failure occurs.