12th USENIX Workshop on Hot Topics in Cloud Computing (HotCloud ’20). Virtual Boston, MA, July 13-14, 2020.
Hojin Park, Gregory R. Ganger, George Amvrosiadis
Carnegie Mellon University
Burstable storage is a public cloud feature that enhances cloud storage volumes with credits that can be used to boost performance temporarily. These credits can be exchanged for increased storage throughput, for a short period of time, and are replenished over time. We examine how burstable storage can be leveraged to reduce cost and/or improve performance for three use cases with different data-longevity requirements: traditional persistent storage, caching, and ephemeral storage. Although cloud storage volumes are typically priced by capacity, we find that each AWS gp2 volume starts with the same number of burst credits. Exploiting that fact, we find that aggressive interchanging of large numbers of small short-term volumes can increase IOPS by up to 100 at a cost increase of only 10–40%. Compared to an AWS io1 volume provisioned for the same performance, such interchanging reduces cost by 97.5%.