How you configure failover with DSA depends on which configuration is used for the DSA environment. For a description of the configurations, see DSA Configurations.
DSA does not support automatic failover. If using the embedded Data Mover DSC, additional configuration is required after failover occurs before Data Mover DSA jobs can be run again.
Configuration 1: DSC Running on the Data Mover Server
When there is no external DSA environment, the active and standby Data Mover daemons are configured with the Data Mover bundled DSC.
In this configuration, DSC, DSA REST, and Teradata ActiveMQ are running on the active Data Mover server. On the standby server, DSC, DSA REST, and Teradata ActiveMQ are turned off. If failover occurs, the Data Mover failover monitor automatically turns on the Data Mover components on the standby server, including DSC, DSA REST, and Teradata ActiveMQ. However, additional configuration is required before Data Mover DSA jobs can be run on the new active Data Mover server.
Refer to the following considerations based on what version of the Teradata system is running on the source and target systems:
| Teradata Version | Action Needed | Description |
|---|---|---|
| Earlier than 16.00 | Yes | Before running any Data Mover DSA jobs, you must go through all of the steps to configure the DSC on the new active Data Mover server. No pre-configuration can occur in this scenario. |
| 16.00 and later | Yes | The DSC on the active and standby servers are registered with the source and target systems during the configuration process, but the DSA ClientHandler cannot be pre-configured to use the standby DSC. If failover occurs, the ClientHandler properties must be updated on all TPA nodes being used and must be restarted. |
Configuration 2: Data Mover using an External DSC
Configuration 2 is used when a Teradata Database with a version earlier than 16.00 has an existing DSA environment and is used for the following:
- Backup and restore
- Copying data with Data Mover using the database as a source or target system
In this configuration, both the active and standby servers use the same external DSC. If a Data Mover failover occurs, the failover monitor starts the new active Data Mover components and the new active Data Mover server calls the external DSC. No DSC configuration or registration is necessary if a Data Mover failover occurs.
If the external DSC fails, you need to register a new DSC with the source and target systems and configure the active and standby Data Mover servers to use this new DSC. There is currently no automatic failover for this type of failure.
Configuration 3: DSC running on the Data Mover server and externally
Configuration 3 is when you use both the Data Mover DSC and an external DSC environment on Teradata Databases 16.00 and later.
For failover, this configuration mirrors Configuration 1. The independent, external DSC is not involved in Data Mover failover scenarios. See DSA Failover Configuration 1 for details.