Graceful Degradation and Fallbacks

In a microservices architecture, a single user request often depends on multiple services. Consider an e-commerce application where a product page displays product details, inventory availability, customer reviews, and personalized recommendations. Each feature might be powered by a different microservice.

Now imagine the Recommendation Service becomes unavailable. Should the entire product page stop working just because personalized recommendations cannot be loaded? Of course not.

Customers should still be able to view product details, check availability, and purchase products. The application might temporarily hide the recommendations section or display a generic list of popular products.

This approach is called graceful degradation. Instead of allowing a partial failure to make the entire application unavailable, the system continues operating with reduced functionality.

A closely related concept is a fallback, which provides an alternative response or behavior when the primary operation fails. Together, graceful degradation and fallbacks help microservices remain useful even when some dependencies are unavailable. Let's understand how these techniques work and how to design them effectively.