Protection mode overview

This topic describes the protection modes supported by OceanBase Database.

Maximum performance mode

Maximum performance is the default protection mode. It favors primary-tenant performance while still protecting user data. In this mode, a transaction can commit as soon as Redo logs are persisted on the primary tenant. Redo logs are replicated to standby tenants asynchronously and do not block commits on the primary. Therefore, primary-tenant performance is not limited by standby replication lag.

Maximum protection mode

Maximum protection provides the strongest data protection and ensures no data loss if the primary tenant fails. In this mode, a transaction can commit only after Redo logs are persisted on both the primary tenant and the strongly synchronized standby tenant.

In maximum protection mode, only one strongly synchronized standby tenant is supported; all other standbys remain asynchronously synchronized. If the strongly synchronized standby is unavailable, the primary tenant stops its write service.

Maximum availability mode

Maximum availability provides the strongest data protection without sacrificing availability. By default, a transaction can commit only after Redo logs are persisted on both the primary tenant and the strongly synchronized standby tenant. When the system detects that the strongly synchronized standby has failed, the primary tenant stops waiting for strong sync and behaves like maximum performance—prioritizing restoration of primary service and tenant availability. After the strongly synchronized standby recovers, the primary automatically returns to strong synchronization and the highest level of data protection again.

In maximum availability mode, only one strongly synchronized standby tenant is supported; all other standbys remain asynchronously synchronized.