Boost Spring Boot Performance with GraalVM Native Images

What is GraalVM

GraalVM is a high‑performance virtual machine that can significantly improve program speed and efficiency, making it well‑suited for microservices. The popular Java framework Quarkus supports GraalVM out of the box, and Spring Boot 2.4 has begun adding GraalVM support to improve startup time, memory consumption, and response latency.

Installing GraalVM

The latest community version is 20.3.0, built on OpenJDK 8u272 and 11.0.9, essentially a derivative of OpenJDK.

The recommended installation tool is SDKMAN , which works like nvm for Node.js, allowing quick installation and switching of JDK versions.

Install a specific version and set it as default:

sdk install java 11.0.9.hs-adpt
sdk default java 11.0.9.hs-adpt

After installation, verify the version:

java -version
openjdk version "11.0.9" 2020-10-20
OpenJDK Runtime Environment GraalVM CE 20.3.0 (build 11.0.9+10-jvmci-20.3-b06)
OpenJDK 64-Bit Server VM GraalVM CE 20.3.0 (build 11.0.9+10-jvmci-20.3-b06, mixed mode, sharing)

Installing native‑image

native‑image is an ahead‑of‑time compiler from Oracle Labs that packages class dependencies and runtime libraries into a single executable, offering fast startup and low memory overhead. GraalVM does not include it by default; you must install it with the gu tool.

# Switch to the JDK installation directory
cd $JAVA_HOME/bin/
# Install native‑image
./gu install native-image

Initialize a Spring Boot 2.4 Project

Create a demo project with Spring Initializr:

curl https://start.spring.io/starter.zip -d dependencies=web \
    -d bootVersion=2.4.1 -o graal-demo.zip

Run the empty project to get baseline metrics (startup ~1135 ms, memory ~480 MB): java -jar demo-0.0.1-SNAPSHOT.jar Check memory usage:

ps aux | grep demo-0.0.1-SNAPSHOT.jar | grep -v grep | awk '{print $11 "\t" $6/1024"MB"}'
/usr/bin/java 480.965MB

Enable GraalVM Support

Add the required dependencies (Spring GraalVM native and context indexer) and the Spring Milestones repository to the Maven pom:

<dependency>
    <groupId>org.springframework.experimental</groupId>
    <artifactId>spring-graalvm-native</artifactId>
    <version>0.8.3</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context-indexer</artifactId>
</dependency>

<repositories>
  <repository>
    <id>spring-milestones</id>
    <name>Spring Milestones</name>
    <url>https://repo.spring.io/milestone</url>
  </repository>
</repositories>

Modify the main class to disable proxy bean methods:

@SpringBootApplication(proxyBeanMethods = false)
public class DemoApplication { ... }

Build the native executable: mvn -Pnative package The build process is lengthy; logs show classlist generation and total build time of about 203 seconds.

The resulting executable is placed in the target directory:

Run the native binary instead of the JAR:

cd target
./com.example.demo.demoapplication

Startup time drops to ~0.215 seconds.

Memory usage falls to ~24.8 MB.

ps aux | grep com.example.demo.demoapplication | grep -v grep | awk '{print $11 "\t" $6/1024"MB"}'
./com.example.demo.demoapplication 24.8203MB

Performance Comparison

Without GraalVM: memory 480.965 MB, startup 1135 ms. With GraalVM native image: memory 24.8203 MB, startup 215 ms.

References

GraalVM – https://www.graalvm.org

Quarkus – https://quarkus.io

SDKMAN – https://sdkman.io/install

nvm – https://github.com/creationix/nvm

Gitee Gist – https://gitee.com/gi2/codes/famcqz6n21iylpg3us7j036