Mapping CRUD to Events - Towards an object to event-sourcing framework

Abstract

Accessing objects in software applications usually breaks down to four basic operations: Create, Read, Update, and Delete (CRUD). The latter is a well-known pattern in software development and web application domains. CRUD has been applied primarily to relational database-backed systems, object-relational mappers (ORMs), and relevant tools since the early ’80s. In the era of cloud computing, though, relational databases are not always the most efficient service to store application data due to the application requirements shifting towards non-functional requirements such as observability. Command Query Responsibility Segregation (CQRS) and Event Sourcing (ES) are a couple of alternative patterns on which one can build applications. However, there is a lack of tooling and guidance, especially for inexperienced practitioners. In addition, as reported in the literature, this approach requires a thorough understanding of the application domain. In this paper, we investigate the possibility of bridging CRUD modeling technics with the CQRS-ES patterns systematically and generically. Upon success, we will be able to build new event-sourced applications in the same manner as we now utilize ORMs and tools to accelerate the process. Moreover, legacy systems might also benefit by enhancing their current operation with an event-source component and, if needed, gradually replacing obsolete parts.