Cloud Index Tracking
Supreeth Shastri, David Irwin · 2018
Cloud spot markets rent VMs for a variable price that is typically much lower than the price of on-demand VMs, which makes them attractive for a wide range of large-scale applications. However, applications that run on spot VMs suffer from cost uncertainty, since spot prices fluctuate, in part, based on supply, demand, or both. The difficulty in predicting spot prices affects users and applications: the former cannot effectively plan their IT expenditures, while the latter cannot infer the availability and performance of spot VMs, which are a function of their variable price. Prior work attempts to address this uncertainty by modeling and predicting individual spot prices based on historical data. However, a single model likely does not apply to different spot VMs, since they may have different levels of supply and demand. In addition, cloud providers may unilaterally change spot pricing algorithms, as EC2 has done multiple times, which can invalidate existing price models and prediction methods.