SpotWeb: Running Latency-sensitive Distributed Web Services on Transient Cloud Servers

Many cloud providers offer servers with transient availability at a reduced cost. These servers can be unilaterally revoked by the provider, usually after a warning period to the user. Until recently, it has been thought that these servers are not suitable to run latency-sensitive workloads due to their transient availability. In this paper, we introduce SpotWeb, a framework for running latency-sensitive web workloads on transient computing platforms while maintaining the Quality-of-Service (QoS) of the running applications. SpotWeb is based on three novel concepts; using multi-period optimization---a novel approach developed in finance---for server selection; transiency-aware load-balancing; and using intelligent capacity over-provisioning. We implement SpotWeb and evaluate its performance in both simulations and testbed experiments. Our results show that SpotWeb reduces costs by up to 50% compared to state-of-the-art solutions while being scalable to hundreds of cloud server configurations.