A set of edge servers in a content delivery network is selected to serve a set of users. Selection comprises constructing a trellis having a number of states at least equal to a number of edge servers in the edge-server set, wherein each state comprises a plurality of nodes, each node corresponding to one of a plurality of candidate edge servers. A fitness function is calculated based on network performance improvement and cost corresponding to each candidate edge server. A trellis-exploration algorithm is used to select the edge-server set by identifying a path through the trellis having optimal path metrics derived from the fitness function. The algorithm provides interconnects between each node of a first state to each of a plurality of nodes in a next state, and for each node in a state, a path is selected that corresponds to a best path metric that connects to a node in a previous state, wherein the best path metric comprises the fitness function. Data signals are transmitted to each edge server in the edge-server set for storage, which are then delivered to requesting client devices.