Performance Comparison of Spring Boot and Quarkus for Cloud‑Native Java Applications

Spring Boot is a widely used Java framework for enterprise applications, while Quarkus is a newer Kubernetes‑native Java framework optimized for GraalVM and native images.

The article compares the two frameworks in terms of architecture, startup time, memory usage, and throughput using reactive implementations (Spring WebFlux and Quarkus reactive) and a test suite built with JMeter and VisualVM.

Key findings: Quarkus native images start up roughly twice as fast as Spring Boot native, build time is shorter (9 min vs 13 min), and the native artifact is smaller (75 MB vs 109 MB). In JVM mode, Quarkus also shows faster startup (20 s vs 39 s) and lower memory consumption.

CPU usage is higher at warm‑up for JVM versions, but stabilizes later. Memory usage is lower for Quarkus, especially in native mode. Response‑time tests show Spring Boot JVM slightly better latency and thread efficiency, while Quarkus excels in low‑resource scenarios.

The article also provides a migration guide from Spring Boot to Quarkus, highlighting Spring API compatibility (DI, Web, Data JPA) and the ability to reuse existing knowledge.

Sample code snippets demonstrate a Spring‑style controller, a Spring Data repository, and a Quarkus service using MicroProfile fault tolerance.

import java.util.List;
import java.util.Optional;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping('/person')
public class PersonController {
    @GetMapping(path = '/greet/{id}', produces = 'text/plain')
    public String greetPerson(@PathVariable(name = 'id') long id) {
        String name = '';
        // ...
        return name;
    }

    @GetMapping(produces = 'application/json')
    public Iterable<Person> findAll() {
        return personRepository.findAll();
    }
}

package org.acme.springmp;

import java.util.List;
import org.springframework.data.repository.CrudRepository;

public interface PersonRepository extends CrudRepository<Person, Long> {
    List<Person> findByAge(int age);
}

import org.eclipse.microprofile.faulttolerance.Fallback;
import org.eclipse.microprofile.faulttolerance.Timeout;
import org.eclipse.microprofile.rest.client.inject.RestClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

@Service
public class PersonService {

    @Autowired
    @RestClient
    SalutationMicroProfileRestClient salutationRestClient;

    @Value('${fallbackSalutation}')
    String fallbackSalutation;

    @CircuitBreaker(delay=5000, failureRatio=.5)
    @Fallback(fallbackMethod = 'salutationFallback')
    public String getSalutation() {
        return salutationRestClient.getSalutation();
    }
}