gRPC: synchronous and asynchronous unary RPC in Java
gRPC, a remote procedure call (RPC) framework, is used for inter microservices communication. The gRPC supports both unary RPC and streaming RPC. In gRPC unary RPC, a client sends a single request and receives a single response. Additionally, an RPC in gRPC can be synchronous or asynchronous. In synchronous RPC, a client call waits for the server to respond. As the name suggests, in asynchronous RPC the server returns the response asynchronously.