HTTP and REST are commonly used protocols for providing synchronous request/response-based communication in microservices. 

HTTP is a protocol that allows clients to send requests to servers and receive responses, and REST is an architectural style that defines how HTTP should be used to provide a consistent interface for clients and servers to communicate with each other.

https://learn.microsoft.com/en-us/dotnet/architecture/microservices/architect-microservice-container-applications/communication-in-microservice-architecture