Envoy vs nginx: What are the differences?

Envoy and Nginx are both open-source, high-performance web servers, but they cater to different needs. Envoy is a service mesh proxy designed for microservices architectures, offering advanced features like load balancing, circuit breaking, and health checks. Nginx excels at static content delivery and traditional web serving, known for its stability and ease of use. Here are the key differences between the two.

1. Architecture: Envoy and nginx have different architectures. Envoy is designed as a service proxy and follows a sidecar architecture, where it runs alongside each service application instance. On the other hand, nginx is a reverse proxy server that typically runs on a separate server and handles incoming client requests. This architectural difference allows Envoy to provide more advanced features like service discovery, load balancing, and circuit-breaking.
2. API Abstraction: Envoy and nginx have different levels of API abstraction. Envoy is designed to provide a more granular control over the underlying network communication, providing a rich set of configuration options through its API. In contrast, nginx provides a more abstract and simplified API, which makes it easier to configure for basic use cases but may limit the flexibility for more complex deployments.
3. Extensibility: Envoy and nginx offer different levels of extensibility. Envoy has a modular architecture that allows users to plug in custom filters and extensions at various network layers, enabling the implementation of custom logic and integration with different systems. Nginx also supports some level of extensibility through modules, but the options are more limited compared to Envoy.
4. Protocol Support: Envoy and nginx have different levels of protocol support. Envoy is built to handle modern protocols like gRPC and HTTP/2 out of the box, along with HTTP/1.1 and TCP. Nginx also supports these protocols but may require additional configuration or modules to handle newer protocols like gRPC effectively.
5. Observability and Debugging: Envoy and nginx provide different observability and debugging capabilities. Envoy has built-in support for distributed tracing, request-level logs, and metrics, making it easier to monitor and analyze the behavior of your services. Nginx also provides logging and metrics capabilities but may require additional setup or third-party tools for tracing and advanced monitoring.
6. Community and Ecosystem: Envoy and nginx have different community sizes and ecosystems. Envoy has gained significant traction in the cloud-native community and has a large and active community supporting its development and maintenance. Nginx has been around for a longer time and also has a strong community, but its ecosystem is more focused on traditional web server use cases.

In summary, Envoy, a service mesh proxy, shines in the dynamic world of microservices, offering advanced functionalities like load balancing and health checks. Nginx, on the other hand, reigns supreme in the realm of static content delivery, known for its stability and ease of use.