Software Architect's Handbook

Communicating with lightweight message protocols

Microservices should communicate using well-known, lightweight message protocols. There is no rule dictating a particular protocol, and microservices can communicate synchronously or asynchronously. A common implementation for microservices is to have them expose HTTP endpoints that are invoked through REST API calls. For synchronous communication, REST is one of the preferred protocols. It is common for REST to be used with JavaScript Object Notation (JSON). Service operations can accept and return data in the JSON format as it is a popular and lightweight data-interchange format.

Some applications may require asynchronous communication. A common messaging protocol used for asynchronous communication ...