To configure HANA system replication between a primary and secondary site, you’ll need to perform several steps. Here’s an overview of the commands involved in the configuration process:

1. Connect to the primary site’s HANA database using the HANA Studio or HANA Cockpit, or by using the hdbsql command line tool.
2. Check the current replication status and configuration:

ALTER SYSTEM GET CONFIGURATION ('systemReplication')

This command will show you the current replication status and settings.

3. If replication is not yet enabled, you’ll need to enable it. Use the following command:

ALTER SYSTEM SET CONFIGURATION ('systemReplication', 'enabled', 'true') WITH RECONFIGURE

This command enables system replication and triggers a reconfiguration.

4. Create the secondary site configuration. Connect to the secondary site’s HANA database and execute the following command:

CREATE SYSTEM REPLICATION CONFIGURATION '<configuration_name>' SITE 'secondary_site' HOST '<secondary_host>' PORT <secondary_port> USER '<replication_user>' PASSWORD '<replication_password>'

Replace <configuration_name>, <secondary_site>, <secondary_host>, <secondary_port>, <replication_user>, and <replication_password> with the appropriate values.

5. Configure the replication mode and other parameters. Execute the following command at the primary site:

ALTER SYSTEM ALTER CONFIGURATION ('systemReplication') SET ('mode', '<sync_mode>') WHERE TARGET = 'secondary_site'

Replace <sync_mode> with the desired synchronization mode. Common options are 'sync', 'async', or 'near_sync'.

6. Start the replication process:

ALTER SYSTEM START REPLICA ADMIN FOR CONFIGURATION '<configuration_name>'

Replace <configuration_name> with the name specified in step 4.

7. Validate the replication setup. Check the replication status using:

SELECT * FROM M_SYSTEM_REPLICATION_STATUS

This command will show you the current replication status.