RPC

A communication protocol that allows a program on one computer to execute code on another computer as if it were a local function call. The idea is to abstract the complexity of network communication so that developers can focus on writing distributed applications without needing to manually handle low-level data transmission, error checking, or socket management.

In practice, an RPC works by having the client program call a stub function, which packages the request, sends it across the network, and waits for a response. On the server side, a corresponding stub unpacks the request, executes the procedure, and returns the result to the client. This process is often invisible to the developer, making remote execution appear nearly identical to calling a local function.

RPC has been a foundational concept in distributed systems for decades. Early implementations included ONC RPC (Open Network Computing RPC) and DCE/RPC (Distributed Computing Environment RPC), both of which influenced later standards. Modern variations of RPC include gRPC (developed by Google), which uses HTTP/2 and Protocol Buffers to support high-performance, language-agnostic communication between microservices.

The importance of RPC lies in its ability to simplify distributed computing. By treating networked services as callable functions, RPC enables modular architectures, service-oriented designs, and scalable microservice ecosystems. However, it also introduces challenges, such as handling latency, ensuring security, and managing failures across unreliable networks. As a result, developers using RPC often need to consider retry logic, authentication, and observability alongside the basic protocol mechanics.