Implementing gRPC.

Published: 2 hours ago (February 5, 2026 at 05:06 PM EST)

3 min read

Source: Dev.to

Core Principles

Protocol Buffers – gRPC employs Protocol Buffers for serialization, allowing efficient binary encoding of data. This reduces message size and minimizes parsing overhead, resulting in faster communication.
Strongly‑typed contracts – APIs are defined with .proto files that specify services, methods, and data types. This creates a consistent interface between client and server and reduces the risk of errors.
Bi‑directional streaming – Clients and servers can exchange messages simultaneously, which is especially useful for large or real‑time data transfers.
Language‑agnostic – Official support exists for C++, Java, Python, Go, and many other languages, enabling teams to choose the most appropriate language without compatibility concerns.

Typical Use Cases

High‑performance applications
Microservices architectures
Real‑time or streaming workloads
Mobile/IoT communication where bandwidth is limited

gRPC is an excellent choice for performance‑centric, scalable APIs in distributed systems. It is ideal for teams experienced in low‑level programming and network communication, enabling fast, reliable APIs.

gRPC vs. REST Comparison

Aspect	gRPC	REST
Protocol	HTTP/2	HTTP/1.1 (or HTTP/2)
Message Format	Protocol Buffers (binary)	JSON, XML (text)
Performance	⚡ Faster (binary serialization)	Slower (text parsing)
Payload Size	Smaller (~3–10×)	Larger
Latency	Lower	Higher
Bandwidth Usage	Lower	Higher
Code Generation	Automatic (from `.proto` files)	Manual or template‑based
Browser Support	Limited (gRPC‑Web required)	Native support
API Style	RPC (function calls)	Resource‑oriented (URIs)
URL Routing	`Service.Method`	RESTful paths (`/resource/id`)
HTTP Methods	Uses POST for all	GET, POST, PUT, DELETE, PATCH
Caching	Difficult (custom logic)	Built‑in (HTTP caching)
Streaming	Bidirectional streaming	Request‑response only
Connection	Persistent (multiplexed)	Per‑request
Learning Curve	Steeper	Easier
Ecosystem	Growing	Mature & established
Documentation	Code‑generated (proto)	Manual documentation
Debugging	Harder (binary format)	Easier (JSON readable)
Mobile Friendly	Good	Very good
IoT/Edge Computing	Excellent	Good
Real‑time Features	Excellent (streaming)	Limited
Interceptors/Middleware	Built‑in	Manual implementation
Error Handling	Standardized (gRPC status codes)	HTTP status codes
Authentication	JWT, OAuth, Certificates	OAuth, API Keys, JWT
Use Cases	Microservices, Real‑time, Mobile	Public APIs, Web services

Quick Start Example

# Clone the repository
git clone https://github.com/your-org/aquaworld-grpc.git
cd aquaworld-grpc

# Build and run the server
mvn clean install
mvn spring-boot:run

Expected Server Output

🐠 ==========================================
🐠 AquaWorld Pet Store gRPC API
🐠 ==========================================
🐠 gRPC Server started on port 9090
🐠 Test with grpcurl: grpcurl -plaintext localhost:9090 list
🐠 ==========================================

Testing with grpcurl

# macOS
brew install grpcurl

# Linux (requires Go)
go install github.com/fullstorydev/grpcurl/cmd/grpcurl@latest

# List available services
grpcurl -plaintext localhost:9090 list

Expected Result

com.aquaworld.grpc.auth.AuthService
com.aquaworld.grpc.order.OrderService
com.aquaworld.grpc.payment.PaymentService
com.aquaworld.grpc.product.ProductService
grpc.reflection.v1.ServerReflection
grpc.reflection.v1alpha.ServerReflection

Follow the repository’s README to test the remaining functionalities.

Versioning via Proto Packages

Recommended approach: version your API using the package name in your .proto files (e.g., package aquaworld.v1;).

Best Practices

Field Numbers

Never reuse field numbers once assigned.
Do not delete fields; instead, mark them as deprecated.

Status Codes

Code	Meaning
`OK`	Success
`INVALID_ARGUMENT`	Client sent invalid data
`NOT_FOUND`	Resource does not exist
`ALREADY_EXISTS`	Duplicate resource
`PERMISSION_DENIED`	Authorization failure
`UNAVAILABLE`	Service temporarily unavailable

Avoid returning UNKNOWN or INTERNAL for client‑side errors.

Rich Error Details

Use gRPC trailers to send structured error metadata, enabling programmatic handling on the client side.

Deadlines & Timeouts

Always set a deadline (context.WithDeadline) to define how long a client will wait for a response.

Retries

Implement retries deliberately; they improve resilience only when combined with idempotent operations and proper back‑off strategies.

Load Balancing

HTTP/2’s long‑lived connections change load‑balancing dynamics. Use gRPC‑aware load balancers (e.g., Envoy, gRPC‑LB) to distribute traffic effectively.

Summary of Advantages

High performance and low latency
Efficient mobile/IoT communication
Real‑time bidirectional streaming
Ideal for microservices and internal APIs
Minimal bandwidth usage

These characteristics make gRPC a strong candidate for modern, performance‑critical distributed systems.