Measuring and Improving the Reliability of Wide-Area Cloud Paths

Many popular cloud applications use inter-data center paths; yet, little is known about the characteristics of these ``cloud paths''. Over an eighteen month period, we measure the inter-continental cloud paths of three providers (Amazon, Google, and Microsoft) using client side (VM-to-VM) measurements. We find that cloud paths are more predictable compared to public Internet paths, with an order of magnitude lower loss rate and jitter at the tail (95th percentile and beyond) compared to public Internet paths. We also investigate the nature of packet losses on these paths (e.g., random vs. bursty) and potential reasons why these paths may be better in quality. Based on our insights, we consider how we can further improve the quality of these paths with the help of existing loss mitigation techniques. We demonstrate that using the cloud path in conjunction with a detour path can mask most of the cloud losses, resulting in up to five 9's of network availability for applications.