Databases that Require Replication Agents

A Replication Agent retrieves transactions from a database log and passes them to the replication system through the Replication Server that manages the database.

There is one Replication Agent per database. Because the Replication Agent is configured when a database is set up for replication, you must know whether a Replication Agent is required before you add a database to the replication system. A user database requires a Replication Agent if:

The database holds primary data that is replicated to other databases managed by the same or different Replication Servers.
The Replication Server manages a database that is a source of replicated stored procedure execution.
You plan to replicate a stored procedure execution from a primary to replicate databases or from a replicate to a primary database. Replication Agent retrieves the procedure call information from the database transaction log. See the Replication Server Administration Guide Volume 1.
The database is the active or standby database in a warm standby application. Replication Agent for a standby database is needed only when you switch to the standby database. See the Replication Server Administration Guide Volume 1.

An RSSD requires a Replication Agent if the Replication Server using that RSSD has a route to another Replication Server; for example:

The Replication Server manages primary data that is replicated to databases managed by other Replication Servers.
The Replication Server manages a database that is a source of replicated stored procedure execution.
The Replication Server is an intermediate site in an indirect route.

An RSSD does not require a Replication Agent if the replication system has only one Replication Server. Replication Agent for ERSSD is managed by Replication Server. It is automatically started when a route is created. You do not need to decide the ERSSD Replication Agent requirements at installation or configuration time of Replication Server.