gRPC and Remote Procedure Calls

Modern distributed systems are built on a foundation of inter-process communication. At the heart of this communication lies a fundamental concept: the Remote Procedure Call (RPC). Before we dive deep into gRPC and its intricacies, let’s understand what RPCs are and why they matter.

Understanding Remote Procedure Calls

At its most basic level, a Remote Procedure Call is exactly what it sounds like: a mechanism that enables one process to call a function (procedure) on another process and receive a response back. Think about your daily coding practice - you’re constantly making function calls to different components and services. The key distinction lies in where these calls are directed:

When you call a function within your application, you’re making a local call (within the same process)
When your application needs to interact with another service, you’re making a remote call (to another process on the same or a different machine)

This distinction becomes crucial in distributed systems, where RPCs form the backbone of how machines communicate with each other.

The RPC Universe

The term “RPC” is incredibly broad, encompassing virtually any form of “out-of-process” communication. Developers have numerous options for implementing remote procedure calls:

HTTP requests
Web Application Messaging Protocol for RPCs over WebSockets
Dedicated RPC frameworks like Apache Thrift, JSON-RPC, or gRPC
Asynchronous approaches using message queues like Apache Kafka

Each of these approaches has its own strengths and use cases. However, they all share a common goal: enabling different parts of a distributed system to communicate effectively.

Enter Modern RPC Frameworks

This is where frameworks like gRPC come into play. Their mission? To abstract away the complexity inherent in remote procedure calls. The ultimate aim is to make calling a remote function feel as natural as calling a local one - though as we’ll see, this ideal isn’t always perfectly achieved.

More to come .. sOOn :) In the following sections, we’ll take a deep technical dive into gRPC, exploring how it works, its key features, and when you might want to use it in your distributed systems…