Test the failover configuration

To test the UniInt failover configuration, use PI ICU to start the interface interactively and view the output.

1. Start the first interface instance interactively using PI ICU.

   The first interface to start assumes the role of primary interface.

2. Check the output to verify that failover is correctly configured.

   Successful failover output would look similar to the following example:

   OPCpi> 1 1> UniInt failover: Successfully Initialized: This Failover ID (/UFO_Id): 1 Other Failover ID (/UFO_OtherId): 2

   The primary interface runs and collects data.

3. Start the second interface instance.

4. Check the output to verify that failover for the second instance is configured correctly.

   The second interface instance assumes the role of backup interface.

5. Stop the primary interface.

6. Verify that the backup interface has detected the absence of the primary instance and has taken over data collection. Examine the output for the following messages:

   > UniInt failover: Interface is attempting to assume the
   "Primary" state.
   Waiting 2 ufo intervals to confirm state of other copy.
   Fri Jun 22 11:43:26 2012
   > UniInt failover: Waited 2 ufo intervals, Other copy has
   not updated our activeId, transition to primary.
   Fri Jun 22 11:43:26 2012
   > UniInt failover: Interface in the "Primary" state and
   actively sending data to PI.

7. Check for data loss in Data Archive.

   For example, use PI ProcessBook to display a data trend.

8. Test failover with different failure scenarios. Verify the level of data loss by checking the data in Data Archive and on the data source.

   For hot failover, there should be no data loss. For warm and cold failover, there will be a short period of data loss during the failover transition.

   For example, test loss of the Data Archive connection for one of the instances.

Once you have tested failover for a successful configuration, stop both copies of the interface, start buffering, configure each interface instance as a service, and then start both copies of the interface.