Definition
Envoy refers to a service proxy, often an open-source project, designed to manage and control network traffic between services in a distributed system. It acts as a universal data plane, abstracting away the complexities of inter-service communication and providing observability into traffic flow. Envoy is crucial for modern cloud-native architectures, enabling robust traffic management, security, and observability. In practice, it intercepts requests, applies policies, and forwards them to the appropriate service, often within a service mesh. This empowers developers and operators to build resilient and secure applications without deep networking expertise. For example, Envoy can be used to implement canary deployments, gradually rolling out new versions of a service to a small subset of users before a full release. It is distinct from a traditional load balancer in its advanced features like dynamic configuration and deep protocol awareness. You will encounter Envoy concepts on cloud security certifications like CCSP and AWS exams.