Failover modes

The AVEVA adapter is capable of supporting client failover. With client failover, you can configure two adapters as part of a redundant group, so that the secondary adapter may take the place of the primary in the event of a connection loss to the failover endpoint or data source.

Failover logic

There are three client failover modes that the adapters can be configured to use:

• Hot

  In hot failover mode, configured components for both the primary and secondary adapters collect and buffer data but only the primary adapter egresses data to the data endpoint. Data from the secondary adapter instance only egresses the buffered data to the endpoint when a failover event occurs and the secondary adapter becomes the primary.

  

• Warm

  In warm failover mode, configured components for the secondary adapter instance start and connect to the data source but do not collect or egress data from the data source. After a failover event occurs, the secondary becomes the primary and begin to collect and egress data.

  

• Cold

  In cold failover mode, you configure the secondary adapter but none of the configured components for the secondary adapter instance start. After a failover event occurs, the secondary adapter becomes the primary and begins to collect and egress data.

  

For more information about failover modes, failover scoring and configuring client-level failover, see Configure adapters in failover.