Introduction to gRPC and How It Works
Published: 2024-05-09 10:06:51

## What is gRPC? 

gRPC is a modern, open-source remote procedure call (RPC) framework that can run anywhere. It enables client and server applications to communicate transparently and makes it easy to build connected systems.  

gRPC is based on the Common Object Request Broker Architecture (CORBA) and Google's Protocol Buffers (Protobuf). gRPC uses HTTP/2 for transport and Protocol Buffers for message serialization. It supports multiple programming languages, making it easy to create cross-platform applications using the cross-platform framework.   

gRPC is efficient and scalable and can be used in a wide range of applications. Use cases for gRPC include distributed systems, microservices, [hybrid Cloud Application Development](https://www.prioxis.com/services/cloud-application-development), and cross-platform mobile apps.  

## How Does gRPC Work?  

To use gRPC, you first need to define your service in a .proto file. This file will contain your message and service definitions. Once you have defined your service, you can generate the necessary code for your programming language of choice. The generated code will provide you with all the necessary client and server stubs that you need to implement your RPC calls.  

On the client side, you only need to call the appropriate method on the generated client stub. The client stub will then send an HTTP/2 request to the server containing the serialized message. On the server side, the corresponding server stub will receive the request and deserialize the message. The server stub will then call the appropriate method on your business logic implementation. Finally, the result will be serialized and sent back to the client over HTTP/2.  

gRPC is a very efficient way to communicate between services. It is also easy to use thanks to its generated code. If you are looking for a modern [RPC framework](https://www.rdglobalinc.com/understanding-grpc-the-modern-rpc-framework/), gRPC is definitely worth considering. 

## Overview of the gRPC Architecture  

gRPC uses HTTP/2 for transport and Protocol Buffers for message serialization. gRPC is designed to be extensible and supports many languages.  
gRPC architecture consists of the following components:  

1) A client library that generates RPC stubs  

2) A server library that implements the RPC API (Application Programming Interfaces)  

3) A message format (Protocol Buffers)  

4) A transport layer (HTTP/2)  

5) An authentication model (TLS/SSL)  

6) A load-balancing strategy (DNS-based or client-side)  

##Difference Between REST and gRPC  
When it comes to setting up communication between services, there are two main camps: those who prefer REST (Representational State Transfer) and those who prefer gRPC (Remote Procedure Calls). Both have their own benefits and drawbacks, which can make choosing the right one for your needs a bit challenging. To help you make that decision, we have put together a comprehensive guide to gRPC and how it stacks up against REST.  

 
gRPC is the latest technology that uses a different approach than REST. Rather than using HTTP requests and responses as REST does, gRPC uses something called Protocol Buffers. Protocol Buffers are a way of encoding data that is much more efficient than JSON or XML. This means that gRPC can send data faster and with less overhead than REST.  

Another advantage of gRPC is that it uses bi-directional streams. This means that both the client and server can send data at the same time, without having to wait for a response first. This makes real-time applications much easier to build with gRPC than with REST.  

On the downside, gRPC requires you to use a specific language (currently either Java or Go) on both the client and server side to work properly. This can be limiting if you want to use a different language on either side. Additionally, because it is still a fairly new technology, there are not as many tools as possible and libraries.  

###The Advantages of Using gRPC  

gRPC has many advantages over other RPC frameworks. It is easy to use, supports multiple programming languages, and has a small footprint. gRPC is also highly scalable and extensible.  
 
Here are the Benefits of using gRPC:  

- Easy to use: gRPC is based on the familiarity of HTTP/2 protocol and uses ProtoBuf for message serialization, making it easy to get started with.  

- Supports multiple programming languages: gRPC supports many popular programming languages such as C++, Java, Python, Node.js, and Go.  

- Small footprint: gRPC has a small footprint and can be easily embedded in applications.  

- Highly scalable: gRPC is designed to be highly scalable and can handle millions of requests per second.  

- Extensible: gRPC allows custom extensions such as authentication, [load balancing, and logging](https://techdocs.f5.com/en-us/bigip-16-0-0/big-ip-dns-implementations/configuring-logging-of-global-server-load-balancing-decisions.html).  

###Use Cases  

1) Web API microservices - where multiple services can be deployed independently but are still able to communicate easily via gRPC protocol over the HTTP/2 transport layer. The advantage here is that developers can deploy their services without worrying about ensuring compatibility caused by version changes or implementation details of other services.  

2) IoT (Internet of Things) - As more devices start talking to each other using protocols like Internet Protocol (IP). There is a need for a reliable messaging system, built upon them which could ensure quick transmission of a message from one endpoint to another. Although having terribly slow data rates or too much latency involved due to the same nature. 

Example: IP-based interaction leveraging the power of gRPC makes it easier & speedy to interoperate these low-speed nodes quickly.  

The following code example shows how to use the gRPC framework for .NET:  

`using Grpc;  
using System;  
namespace grpc_dotnet_example  
{  
   class Program  
   {  
       static void Main(string[] args)  
       {  
           Channel channel = new Channel("127.0.0.1:50051", ChannelCredentials.Insecure);  
           var client = new Greeter.GreeterClient(channel);  
           String user = "World";  
           var reply = client.SayHello(new HelloRequest { Name = user });  
           Console.WriteLine("Greeting: " + reply.Message);  
           channel.ShutdownAsync().Wait();  
           Console.WriteLine("Press any key to exit...");  
           Console.ReadKey();  
  } 
    }  
     }` 

##Conclusion  
gRPC is a powerful technology that enables developers to create distributed applications with ease. It provides an efficient and reliable way of communication between services, making it ideal for modern microservices-based architectures. By understanding the basic concepts behind gRPC, such as request/responses, streaming, and bi-directional streaming, you can leverage its flexibility and scalability to build robust applications quickly and efficiently. gRPC is sure to be here for a long time, with its growing popularity in the development community due to many advantages over traditional RESTful APIs,