1. A method of managing applications on an application execution system, the method comprising: determining, by one or more processors, a number instances a first application type is in a busy state at each respective time interval in a first plurality of time intervals; computing a first running average for the busy state of the first application type, based upon the number of instances of the first application type that are in a busy state, at a first application server, at each respective time interval of a first subset of the first plurality of time intervals; and sending a removal request to remove the first application server from a corresponding data structure that specifies which of a plurality of application servers accept service requests for the first application type when the first running average for the busy state meets a first removal criterion.