Suitability of NoSQL systems — Cassandra and ScyllaDB — For IoT workloads

Motivated by the increasing trend of storing data for web applications in fast NoSQL systems, in this paper, we experiment with the leading NoSQL datastore — Cassandra — and a latest generation re-design of Cassandra — ScyllaDB — meant to deliver bleeding-edge performance on modern multicore machines. We evaluate the scalability claim of ScyllaDB, in terms of the number of clients, and provide diagnostic evidence through OS-level metrics, such as, disk utilization and cache-miss rates. Specifically we are motivated by the need to store large amounts of IoT-generated data in nearby datastores. Our evaluation is the first in the line of objective benchmarking of these two technologies that are finding widespread adoption in data centers and other modern computing platforms. For example, we find hitherto unreported performance instability of ScyllaDB when the servers are replicated while we identify the root cause of improved read performance of ScyllaDB compared to Cassandra.