Message serialization in Spring Boot - Performance & Optimization

Performance: Message serialization

MEDIUM IMPACT

Message serialization affects the speed of data transfer between services and the time to process messages in the application.

Sending data between microservices

Spring Boot

public record User(String name, int age) {}

// Using JSON with Jackson
ObjectMapper mapper = new ObjectMapper();
String json = mapper.writeValueAsString(user);
outputStream.write(json.getBytes(StandardCharsets.UTF_8));

JSON serialization is faster and produces smaller messages, improving network and CPU efficiency.

📈 Performance Gainreduces message size by 70%, processing time under 20ms

Sending data between microservices

Spring Boot

public class User {
  private String name;
  private int age;
  // getters and setters
}

// Using default Java serialization
ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
out.writeObject(user);

Default Java serialization is slow and produces large message sizes, increasing network latency and CPU usage.

📉 Performance Costadds 50-100kb per message, blocks processing for 50-100ms

Performance Comparison

Pattern	CPU Cost	Message Size	Network Impact	Verdict
Default Java Serialization	High	Large (~50-100kb)	High latency and bandwidth use	[X] Bad
XML Serialization	Medium	Very Large	High latency and bandwidth use	[!] OK
JSON Serialization	Low	Medium	Efficient network use	[OK] Good
Binary Serialization (Protobuf)	Very Low	Small	Minimal latency and bandwidth	[OK] Good

Rendering Pipeline

Message serialization impacts the server processing stage before sending data over the network. Efficient serialization reduces CPU time and network payload size, speeding up data delivery.

→Server Processing

→Network Transfer

→Client Processing

⚠️ BottleneckServer Processing (serialization CPU cost)

Optimization Tips

1Avoid default Java serialization for network messages due to size and speed issues.

2Prefer JSON or binary formats like Protobuf for faster serialization and smaller messages.

3Set explicit content types in APIs to ensure efficient serialization formats are used.

Performance Quiz - 3 Questions

Which serialization format generally produces the smallest message size?

A Binary formats like Protobuf

B XML

C Default Java serialization

D Plain text

DevTools: Network

How to check: Open DevTools, go to Network tab, inspect the size and timing of API responses or messages.

What to look for: Look for large payload sizes and long transfer times indicating inefficient serialization.