Experimental Assessment of NoSQL Databases Dependability

NoSQL databases are the response to the sheer volume of data being generated, stored, and analysed by modern users and applications. They are extremely scalable horizontally and store data with less rigid structures than the relational ones. NoSQL databases are known to compromise consistency in favour of availability, partition tolerance, and performance. Several studies evaluated the performance of these databases, but the users also need to understand how they behave in the presence of faults and quantify the impact of those faults. This paper presents an experimental evaluation of NoSQL databases' dependability using fault injection, which compares three widely used NoSQL engines based on how they perform in the presence of operator faults. The results show clearly that many times the integrity of the data is affected, even in the presence of simple faults. It is also shown how different databases handle the workloads and the faults differently, evidencing that users must carefully select the solution to use in their systems.