Deconstructing Alibaba Cloud's Preemptible Instance Pricing

Alibaba Cloud's preemptible instances are IaaS instances sold using an auction, similar to the spot instances offered by Amazon Web Services (AWS). Clients purchase them by bidding. The instances are terminated when supply is insufficient, or when the client's bid is lower than the "market price"- which Alibaba Cloud publishes ever so often. We collected Alibaba Cloud's preemptible price traces from November 2018 to July 2021. This work analyzes the traces, and shows evidence that they experienced sharp lateral behavioral changes over time. We characterize the traces before and after these events. Our analysis highlights features in the traces that seem to be artificially engineered by an underlying pricing mechanism. Since engineered features may abruptly change, they are particularly interesting to clients planning their bidding strategy, or scholars who study them (e.g., to design new pricing mechanisms on the basis of real-life data).