Client layer becomes bottleneck: workload analysis of an ultra-large-scale cloud storage system

Recent years have witnessed the fast development of file and storage systems. Many improvements of file and storage systems are inspired by Workload analysis, which reveals the characteristics of I/O behavior. Although cloud storage systems are becoming increasingly prominent, few real-world and large-scale cloud storage workload studies are presented. Alibaba Cloud is one of the world's largest cloud providers, and we have collected and analyzed workloads from Alibaba for an extended period. We observe that modern cloud network architecture can easily handle the peak load during busy festivals. However, the client layer is the system bottleneck during the peak period, which calls for further optimization. We also find that the workload is heavily skewed toward a small percentage of virtual disks, and its distribution conforms 80/20 rule. In summary, the characteristics of such a large-scale cloud storage system in production environments are important for future cloud storage system modifications.