For HANA system replication (HSR), the secondary node doesn’t accept any connections at all. Once the backup is configured, the Azure Backup service pings periodically and fails. Sometimes, these failed attempts reflect on the primary node. After multiple failures, the user is locked, and then the primary node starts to fail with ODBCConnectionError. We’ve observed that all users don’t experience this issue. We recommend you/SAP to investigate the cause of users getting locked in the primary node when user connection fails on the secondary node.
Once you run the pre-registration script, the user information is updated with new password on the primary node. Then the connection to attempt backup will be re-established. But, you might again experience the same scenario.
Also, the backups (full backups) that fail on the secondary node create alerts.
To avoid the above issues, we recommend you to stop protection for a node after it becomes secondary (so that connections aren’t attempted and user is not locked) and resume protection on it, once it becomes primary. If you don’t face this locking situation on their HSR setups and are comfortable with alerts being raised, you can configure backups on both the nodes so that the service handles the take-over and fail-back.