A method comprising: distributing, by a first plurality of network configuration controllers (210, 570) of a controller device (108, 208) and using a consistent hashing algorithm, a plurality of connection sessions with a plurality of network devices (19, 219) among the first plurality of network configuration controllers; monitoring, by the controller device, a number of connection sessions maintained by each of the first plurality of network configuration controllers; adding, by the controller device and based on monitoring the number of connection sessions maintained by each of the first plurality of network configuration controllers, an additional network configuration controller (210, 570) to the first plurality of network configuration controllers to form a second plurality of network configuration controllers (210, 570); in response to adding the additional network configuration controller to the first plurality of network configuration controllers, re-distributing, by the second plurality of network configuration controllers and using the consistent hashing algorithm, one or more connection sessions of the plurality of connection sessions among the second plurality of network configuration controllers; determining, by the controller device, that a network configuration controller of the second plurality of network configuration controllers has stopped working; and in response to determining that the network configuration controller of the second plurality of network configuration controllers has stopped working, re-distributing, by the second plurality of network configuration controllers using the consistent hashing algorithm, the one or more connection sessions of the plurality of connection sessions among the second plurality of network configuration controllers, wherein determining, by the controller device, that the network configuration controller of the second plurality of network configuration controllers has stopped working comprises: periodically registering, by each of the second plurality of network configuration controllers, with the controller device; and determining, by the controller device, that the network configuration controller has failed to register with the controller device. distributing, by a first plurality of network configuration controllers (210, 570) of a controller device (108, 208) and using a consistent hashing algorithm, a plurality of connection sessions with a plurality of network devices (19, 219) among the first plurality of network configuration controllers; monitoring, by the controller device, a number of connection sessions maintained by each of the first plurality of network configuration controllers; adding, by the controller device and based on monitoring the number of connection sessions maintained by each of the first plurality of network configuration controllers, an additional network configuration controller (210, 570) to the first plurality of network configuration controllers to form a second plurality of network configuration controllers (210, 570); in response to adding the additional network configuration controller to the first plurality of network configuration controllers, re-distributing, by the second plurality of network configuration controllers and using the consistent hashing algorithm, one or more connection sessions of the plurality of connection sessions among the second plurality of network configuration controllers; determining, by the controller device, that a network configuration controller of the second plurality of network configuration controllers has stopped working; and in response to determining that the network configuration controller of the second plurality of network configuration controllers has stopped working, re-distributing, by the second plurality of network configuration controllers using the consistent hashing algorithm, the one or more connection sessions of the plurality of connection sessions among the second plurality of network configuration controllers, wherein determining, by the controller device, that the network configuration controller of the second plurality of network configuration controllers has stopped working comprises: periodically registering, by each of the second plurality of network configuration controllers, with the controller device; and determining, by the controller device, that the network configuration controller has failed to register with the controller device. periodically registering, by each of the second plurality of network configuration controllers, with the controller device; and determining, by the controller device, that the network configuration controller has failed to register with the controller device.