A service appliance is installed between production servers running service applications and service users. The production servers and their service applications provide services to the service users. The service appliance replicates the service data of service applications and monitors the service application. If the service appliance detects that the service application has failed or is about to fail, the service appliance takes control of the service. Using the replica of the service data, the service appliance responds to service users in essentially the same manner as a fully operational service application and production server and updates its replica of the service data as needed. When the service appliance detects that the service application has resumed functioning, the service appliance automatically synchronizes the data of the service application of the production server with the service appliance's data and returns control of the service to the service application and its production server.
