Dynamic Network Scheduler for Cloud Data Centres with SDN

The presented dynamic network scheduler improves the fairness and efficiency of network utilization in a Cloud data centre. The proposed design utilizes a directed graph which represents the network comprising routers, switches, physical hypervisors, and virtual machines (VMs) as graph nodes, and represents the physical network connections as weighted edges. The edges have a guaranteed transmission rate derived from the number of devices sharing an outgoing link with a defined bandwidth. Moreover, to maximize utilization of the resources, each node gets a deserved rate dynamically depending on the measured utilization metrics. A VM throttles up or down its traffic up to its deserved rate. The conceptual design of a dynamic network scheduler is further prototypically implemented and evaluated. The implementation uses Software Defined Networking (SDN) with OpenFlow, Ryu SDN controller, and Open vSwitch as software switch on the hypervisor level. The presented dynamic network scheduler uses OpenFlow for monitoring and applying flows to control the link bandwidth. The evaluation shows that the dynamic network scheduler maximizes fairness in resource sharing while minimizing the unutilized resources.