Comparison of Java Microservice Frameworks: Spring Cloud, Vert.x, SparkJava, Micronaut, Javalin, and Quarkus

Overview

Spring Boot is easy to set up but consumes a lot of memory; many new Java micro‑service frameworks aim to be lightweight because of Spring Boot’s heaviness.

Java Microservice Framework No.1 – Spring Cloud

Introduction

Spring Cloud benefits from the mature Spring ecosystem, making it easy to adopt without a dedicated architect.

However, it requires additional infrastructure such as a service‑discovery server, a gateway, a distributed configuration center, request tracing, cluster monitoring, and multiple servers for scaling.

30‑second Load Test

Memory before test

Image shows memory usage of 304 MB.

Memory during test

Image shows memory usage of 1.5 GB and CPU at 321%.

Vert.x – Reactive Toolkit for Java

Introduction

Vert.x is a reactive toolkit that can be used alongside Spring Boot; it provides many micro‑service components and is used by frameworks such as Apache ServiceComb.

30‑second Load Test

Memory before test

Image shows memory usage of 65 MB.

Memory during test

Image shows memory usage of 139 MB and CPU at 2.1%.

Summary

A Vert.x service packs into a ~7 MB JAR, runs directly on the JVM without a servlet container, and can be deployed many per 1‑core 2 GB server.

Reference: VX‑API‑Gateway documentation .

Other Java Microservice Frameworks

SparkJava

JAR ~10 MB, memory 30‑60 MB, performance comparable to Spring Boot.

Micronaut

Supports Java, Groovy, Kotlin; lightweight, fast startup, low memory, multi‑language, dependency injection, built‑in cloud‑native features.

Javalin

Easy to learn, flexible, JAR 4‑5 MB, supports multiple languages, embedded Jetty, simple source code (~2 000 lines).

Quarkus

Fast startup, JAR ~10 MB, documentation relatively scarce.

Spring Boot Learning Resources

SpringBoot+Mybatis Multi‑module Project Tutorial

Elegant Redis Operations with SpringBoot

Springboot Thread Pool Usage and Extension