A first control node and a method therein for selecting the first control node or a second control node to act as a server are provided. The first and second control nodes are comprised in an overlay network. The first control node obtains a first indication relating to a ranking of a suitability of the first control node to act as the server. Furthermore, the first control node receives a second indication from the second control node. The second indication relates to a ranking of a suitability of the second control node to act as the server. Then, the first control node selects, based on the first and second indications, one of the first and second control nodes to act as the server for managing a master representation of a distributed shared memory being accessible within the overlay network.