CREATE: Correlation enhanced traffic matrix estimation in Data Center Networks

Understanding the pattern of end-to-end traffic flows in Data Center Networks (DCNs) is essential to many DCN designs and operations (e.g., traffic engineering and load balancing). However, little research work has been done to obtain traffic information efficiently and yet accurately. Researchers often assume the availability of traffic tracing tools (e.g., OpenFlow) when their proposals require traffic information as input, but these tools may generate high monitoring overhead and consume significant switch resources even if they are available in a DCN. Although estimating the traffic matrix between origin-destination pairs using only basic switch SNMP counters is a mature practice in IP networks, traffic flows in DCNs are notoriously more irregular and volatile, while the large number of redundant routes in a DCN further complicates the situation. To this end, we propose to utilize the service placement logs for deducing the correlations among top-of-rack switches, and to leverage the uneven traffic distribution in DCNs for reducing the number of routes potentially used by a flow. These allow us to develop an efficient CoRrelation Enhanced trAffic maTrix Estimation (CREATE) method that achieves high accuracy. We compare CREATE with two existing representative methods through both experiments and simulations; the results strongly confirm the promising performance of CREATE.