For Application Service at the Edge, the application routing plug-in uses an application archive (EAR) and context roots to map requests to the correct application server. You also can specify requests that should not be considered for Application Service at the Edge by using the URIs to always process at origin fields.
The failover codes setting allows you to specify HTTP return codes that should cause the Edge application server to stop receiving processing requests. If the application server located on the Edge Server machine generates one of the specified failover codes, Edge processing will be suspended and all requests will be serviced by the back-end application server until one of the following things happens: