1. A computer-implemented method, operable in a network comprising multiple service endpoints, said service endpoints running on a plurality of devices, wherein said multiple service endpoints form one or more sub-clusters, and, the method operable on a device comprising hardware including memory and at least one processor, the method comprising: (A) defining a group from an arbitrary set of nodes comprising service instances across the machines of said 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; (B) in response to a request made at a node the group, (B)(1) dynamically determining a service type of the request; and (B)(2) based on the type of the request, selecting one or more nodes in said group to be responsible for processing said request.