Helios serves as Amazon’s internal service mesh, facilitating communication and management of microservices. It provides a unified control plane across the Amazon Web Services infrastructure, enabling services to discover, connect, and authenticate with each other. As an example, when a customer places an order on Amazon, multiple microservices responsible for inventory, payment processing, and shipping communicate through this service mesh to fulfill the request.
The importance of this system lies in its ability to manage the complexity inherent in a large-scale, distributed system. It offers benefits such as improved reliability, scalability, and security by handling tasks like load balancing, traffic management, and mutual TLS authentication. Historically, the adoption of a service mesh architecture became necessary as Amazon transitioned from monolithic applications to a microservices-based approach, requiring a more sophisticated way to manage inter-service communication.