CQRS by Example

Optimizations and Edge Cases

Although Applications designed with different Data Models and asynchronous syncing mechanisms perform well, things may go sideways at runtime. Getting to know the challenges and quirks of CQRS systems will help us avoid them before deploying to production.

In this chapter, we’ll explore how to use multiple Read Models, improve Projection performance via incremental builds, rebuild corrupted Projections, store and recover non-captured Events, and avoid the effects of duplicated Events.

Relying on Multiple Read Models

With CQRS, a powerful technique is to rely on multiple Read Models to adjust performance. Continuing with the last chapter’s Timeline use case, we have a complex edge case left to be solved: the case ...