Google gRPC

Java gRPC (Google Remote Procedure Call) is a efficient, open-source framework that leverage the communication between the multiple distributed systems. gRPC allows applications to invoke methods on remote servers communication as if they are local, also abstracting the high complexity of network channels. gRPC built on HTTP/2, leverages advanced features to offer improved the application performance, scalability, and efficiency.

Core Concepts of gRPC

1. Remote Procedure Calls (RPCs)

Java gRPC is built on the RPC(Remote Procedure Call) model. RPC model help a client to execute a method on a system server as if it is a local procedure call. The user sends a client request to the server, the gRPC server processes it and sends processed data response to the client. This abstraction simplifies the streaming data processing and the complexity of network interactions, it also do make the distributed systems easy to develop and manage the data processing.

2. Protocol Buffers

gRPC utilizes Protocol Buffers also aka protobufs for defining the data structure and RPC service methods. Protocol Buffers is a natural language, serialized format and natural platform developed by Google tech stack. Developer can define the RPC service methods and the protocol message types in a .proto file, then by using plugins and compiler generate the respective language code for client and server.

3. HTTP/2 Transport

gRPC utilize the HTTP/2 as its transport protocol to communicate between client and gRPC server, which has many benefits over HTTP/1.x, it includes:

• Connectivity Multiplexing: It sends concurrently multiple requests and responses between client and server systems over a single connect.
• Header Compression: Compress the request and response header size to improve performance.
• Data Stream Priority: It supports multiple data streaming based on priority.

How the gRPC (Google Remote Procedure Call) Works

1. Define the Service

Declare the protobuf RPC messages and method into the .proto file, which will describe the service contract and data types used in gRPC communication.

2. Generate Code

You can use the the Protocol Buffers compiler (protoc) or plugins (For example – protobuf-maven-plugin ) to generate code in your chosen programming languages. This code includes data classes and RPC service stubs for the client and server.

3. Implement the Service

On the service implementation, you can implement the business logic into RPC methods in the server side by implementing gRPC methods and client side, use the generated client code to make calls to the server.

4. Call the Service

The client can use the generated client stub code to call the service RPC methods, sending requests and receiving responses by using Java gRPC with HTTP/2 protocol.

Benefits of gRPC

• High Performance: gRPC is designed for high performance with low latency, thanks to HTTP/2 and efficient data serialization by Protocol Buffers.
• Data Streaming: gRPC supports different types of streaming (client-side, server-side, unidirectional, bidirectional), which is ideal for real-time data streaming applications.
• Multi Language Support: gRPC supports multiple programming languages, facilitating communication between services written in different languages. e.g. Java, Python etc.
• Error Handling Framework and Deadlines: gRPC provides detailed error codes and supports setting deadlines and timeouts for RPC calls, enhancing reliability and control.

Use Cases for gRPC

• Microservices Architectures: gRPC’s efficiency and cross-language support make it a natural fit for microservices environments.
• Real-Time Applications: Its support for streaming makes Java gRPC suitable for real-time applications such as chat systems and live data feeds.
• High-Performance Systems: Ideal for systems that require low latency and high throughput, such as financial services and gaming platforms.