For a cascade replication that replicates data unidirectionally across a chain of databases, create a configuration for each pair of databases in the chain.
Data Replication does not support cascade replication for configurations that have an Apache Kafka target.
Create a replication configuration for each pair of databases in a chain.
For each configuration, run InitialSync. Begin with the last configuration in the cascade replication and end with the first configuration in the cascade replication.
On the
Server Manager
tab >
Schedules
view, create a schedule for each configuration.
On the
Server Manager
tab >
Tasks
view, perform the following steps for each Extractor task in the configurations in the cascade replication, beginning with the second configuration:
Do not perform these steps for the first configuration in the cascade replication.
Right-click the Extractor task in the
Name
column of the Tasks and Tasks Dependencies list and click
Edit
, or select the Extractor task in the
Name
column and click the
Edit
icon button in the Tasks and Task Dependencies toolbar.
The
Editing
dialog box appears.
In the
Command
field, enter SKIP_DEFAULT_TX=N to disable loopback avoidance. The following image shows this view:
If you do not want to disable loopback avoidance, use the default setting of SKIP_DEFAULT_TX=Y. This setting replicates only the changes that originate on the database immediately before the current database in the cascade replication and skips the changes that originate on preceding databases in the cascade replication. For example, when replicating changes from Database B to Database C, Data Replication skips the transactions that originated on Database A and replicates only the changes that originated on Database B.
Click
Save
.
Repeat these steps for the remaining configurations in the cascade replication that contain Extractor tasks.
Run the replication schedule for each configuration.
From any database in the chain, Data Replication replicates forward all the changes that originally occurred on that database, unless you specified SKIP_DEFAULT_TX=Y in step 4.