Compare API Gateway Kubernetes Ingress Service Mesh

Feature	API Gateway	Kubernetes Ingress	Service Mesh
Purpose	Centralized entry point for clients to access microservices, provides abstraction and protection from direct client requests.	Provides routing for incoming connections to cluster services, enables exposing services to the internet.	Provides advanced traffic management features for microservices communication to improve reliability and performance.
Scalability	Typically horizontally scalable by adding instances, provides centralized management of access to microservices.	Horizontally scalable by adding ingress controllers, provides routing within the cluster.	Horizontally scalable by adding proxies, provides flexible and scalable traffic management within microservices.
Routing	URL-based routing, request transformations (header manipulation, request data mapping, payload compression, etc.).	Path-based routing within the cluster using ingress rules, no request transformation capabilities.	Advanced routing (load balancing, traffic shaping, circuit breaking, etc.), traffic flow control between services, sophisticated traffic management strategies (canary releases, blue-green deployments, A/B testing, etc.).
Security	Authentication, authorization, encryption, SSL termination.	SSL termination, basic security.	mTLS encryption, fine-grained security policies (certificate validation, peer identity verification, etc.).
Monitoring & Management	Request logging, performance monitoring, API management, health checks.	Limited monitoring and management capabilities.	Advanced traffic management features for microservices communication to improve reliability and performance.