Profiling and analyzing the I/O performance of NoSQL DBs

The advent of the so-called NoSQL databases has brought about a new model of using storage systems. While traditional relational database systems took advantage of features offered by centrally-managed, enterprise-class storage arrays, the new generation of database systems with weaker data consistency models is content with using and manag- ing locally attached individual storage devices and providing data reliability and availability through high-level software features and protocols. This tutorial aims to review the architecture of selected NoSQL DBs to lay the foundations for understanding how these new DB systems behave. In particular, it focuses on how (in)efficiently these new systems use I/O and other resources to accomplish their work. The tutorial examines the behavior of several NoSQL DBs with an emphasis on Cassandra - a popular NoSQL DB system. It uses I/O traces and resource utilization profiles captured in private cloud deployments that use both dedicated directly attached storage as well as shared networked storage.