Inbound replication uses a replication channel configured in HeatWave Service to copy transactions from another location to a DB system. The channel connects the source (a MySQL instance or another DB system) to the replica (a DB system), and copies data from the source to the replica.

Asynchronous replication means that the replica does not need to be running and connected to the source all the time. It can pick up new updates whenever it is online and reconnects.

A replica DB system can connect to only one MySQL source. The source server does not control the DB system replica and does not need to have permission to write to it. The replica uses the configured replication channel to connect to the source, providing a set of replication user credentials. Over the connection formed by the channel, the replica retrieves committed transactions from the source. Then the replica writes those transactions to its own copy of the databases.

Impact of the DB System Operations on the Replication Channel

The DB system operations affect the replication channel:

• If you stop the DB system, it stops any enabled channels and changes its state to Needs Attention.
• If you delete the DB system, it deletes any channels attached to the DB system.
• If you restart, upgrade, or update a DB system, enable or disable high availability, or perform a switchover, it temporarily suspends the channel replication while the operation is ongoing. When the operation is complete, replication is resumed. The channel state changes to Updating while the channel is being resumed.