FME Engines process job requests by running FME Workspaces. Each FME Engine processes a single request at a time. FME Server processing can be scaled by adding additional FME Engines to the same computer or to separate computers within the same distributed FME Server environment.
In a distributed environment FME Engines run on a computer or computers that are separate from the FME Server host. Administrators can configure the FME Engines to register with a failover FME Server host, which acts as a backup if the primary FME Server host fails.