Maximum number of engines on FME Server in Active/Passive failover architecture

Background

If FME Server is configured for Active/Passive failover with engines running on both, the active and the passive host, we want to specify the maximum number of licensed engines on both hosts. The parameter FAILOVER_ENGINE_AUTOCONNECT will be set to false. This will make sure that the maximum number of licensed engines will be available at all times, no matter whether a failover happens or not.

Symptom

Currently it is not possible to specify the maximum number of licensed engines on both hosts via the WebUI in an Active/Passive failover architecture with engines running on both hosts. The WebUI will display a notification that indicates that the maximum number of engines is reached:

Workaround

1. Set number of engines to the maximum on active host
2. Set the number of engines to 0 on the passive host
3. Stop the services of the active host
4. Passive host will become the active host
5. Set number of engines to the maximum on active host (previously passive)
6. Start the services of the host that were stopped in step 3

Now both hosts will have the maximum number of licenses specified.