Foundations of Scalable Systems

Chapter 13. Distributed Database Implementations

In the previous three chapters, I’ve described the various distributed system principles and architectures that are widely employed in scalable distributed databases. These make it possible to partition and replicate data over multiple storage nodes, and support different consistency and availability models for replicated data objects.

Precisely how specific databases build on these principles is highly database dependent. Different database providers pick and choose among well-understood approaches, as well as designing their own proprietary mechanisms, to implement the software architecture quality attributes they wish to promote in their products. This means databases that are superficially similar in their architectures and features will likely behave very differently. Even implementations of the same feature—for example, primary election—can vary significantly in terms of their performance and robustness across databases.

Evaluating a database technology for a specific use case therefore requires both knowledge and diligence. You need to understand how the basic architecture and data model of a candidate technology match your requirements in terms of scalability, availability, consistency, and of course other qualities such as security that are beyond the scope of this book. To do this effectively, you need to delve under the hood and gain insights into precisely how high-priority features for your application work. I don’t ...