A Close Look at Shared Resource Consumption in NoSQL Databases for Accurate Accounting

A NoSQL database plays an essential role in all parts of today's multi-tenant large-scale IT services. Accurate information about per-tenant resource accounting is invaluable for optimal service management. However, there is a lack of study on the characteristics of resource consumption by multi-tenants in NoSQL database services, particularly for those resources consumed as part of activities asynchronously triggered by requests accumulated over time from multiple tenants. According to our investigation, this shared resource usage takes up a significant portion of total resource consumption in NoSQL databases.We assert that an accurate understanding of the shared resource consumption pattern is required to design correct and effective techniques for resource management. To this end, we conduct a detailed investigation of the shared resource consumption in popular NoSQL databases. Our focuses are to find out what portion of the overall resource consumption occurs in a shared manner, what type of operations cause them, and what effect the workload intensity has on the amount of shared resource consumption. We have developed a set of techniques for monitoring, recording, and analyzing the resource consumption data toward answering these questions. Our investigation revealed that the shared resource consumption can be as large as 30% of the total resource consumption, implying that resource accounting based only on directly causal events, may lead to underestimation of the true amount. We believe our study highlights the importance of shared resource accounting and provides crucial insights for building accurate resource accounting techniques.