This topic describes two consensus protocols that are supported by OceanBase Database.
In OceanBase Database, a row of data is stored and used on multiple nodes. Data includes data persisted to disks and data in the memory. Consistency between data replicas is maintained based on a consensus protocol. OceanBase Database supports two consensus protocols:
Multi-Paxos protocol, which ensures lossless data recovery for followers when the leader fails. This protocol lays a foundation for high availability of OceanBase Database. For more information, see Paxos protocol.
Consensus protocol based on leader-follower replication (asynchronous replication), which ensures lossy data recovery for followers when the leader fails. This protocol lays a foundation for read-only replicas and primary/standby clusters. For more information, see Distributed election.
OceanBase Database implements both protocols by replicating the redo logs of transactions. For more information about redo logs, see Multi-replica log synchronization.