A method is operable in a network comprising multiple service endpoints, the service endpoints running on a plurality of devices, wherein the multiple service endpoints form one or more sub-clusters. The method includes defining a group from an arbitrary set of nodes comprising service instances across the machines of the one or more sub-clusters, wherein each node in the group assumes one or more discrete responsibilities involved in processing of a request across the group. In response to a request made at a node the group, the service type of the request is dynamically determined; and, based on the type of the request, one or more nodes in the group are selected to be responsible for processing the request.