What Is a Service Mesh and Istio?
A service mesh is a decentralized application infrastructure for making service-to-service communication safe, reliable, and understandable.
A service mesh uses a "service proxy" deployed with each application instance to facilitate this functionality. A service proxy understands Layer 7 requests and messages and can route, secure, observe, and apply policy to these messages consistently and independently of how the service is implemented. The proxies deployed in a single cluster domain form the "mesh."
Istio is an open-source service mesh, which allows you to connect, secure, and control the traffic for your microservices in a declarative and non-intrusive way much like Kubernetes.
Some of the features that Istio enables for cloud-native applications:
Intelligent routing and client-side software load balancing
Resilience against service and network failures
Policy enforcement between services
Observability of your L7 communication
Securing service to service communication