High availability and disaster recovery (HADR) is a Db2 database replication feature that provides a high availability solution for both partial and complete site failures. HADR protects against data loss by replicating data changes from a source database, called the primary database, to one or more target databases, called the multiple standby databases.
In an HADR environment, one database instance acts as the current primary database that is used by the applications. Synchronization with the standby databases occurs by rolling forward transaction log data generated on the primary database which is then shipped to the standby databases.
