The purpose of a HotStandby (HSB) replication protocol is to carry the transaction results safely from the primary server to the secondary server. solidDB offers both synchronous (2-safe) and asynchronous (1-safe) replication protocols. Together with various durability levels (see Durability and logging), the replication protocol can achieve a balance between performance and endurance for the HSB system.

You can set the safeness level as a server default by using the parameter HotStandby.SafenessLevel, control the replication delay that is involved with 1-safe replication by using the HotStandby.1SafeMaxDelay parameter, or set the 2-safe acknowledgment policy by using the HotStandby.2SafeAckPolicy parameter. For more information, see HotStandby section.

The safeness level can also be set dynamically by using the SET SAFENESS and SET TRANSACTION SAFENESS statements, see SET SAFENESS and SET TRANSACTION SAFENESS.