Migrating Spring Boot apps to GraalVM by Alina Yurenko, Daniel Garnier-Moiroux

GraalVM native image compilation offers significant benefits:

• Faster startup times (70ms vs 1.7s)
• Lower memory usage (3-5x less)
• Comparable peak throughput to JVM when optimized

Key challenges when migrating to native:

• Reflection must be configured explicitly
• Resources and serialization need special handling
• Dynamic class loading and runtime code generation require configuration
• Cross-platform compilation limitations

Spring Boot 3.x provides native support through:

• Built-in AOT processing
• Automatic hint generation
• Curated dependency list compatible with native image
• Test support with @EnabledInNativeImage

Best practices for native migration:

• Keep developing and testing on JVM
• Use the tracing agent to identify required configurations
• Apply Profile Guided Optimizations (PGO) for peak performance
• Use latest Spring Boot version for better native support
• Avoid conditional beans and runtime profile evaluation

Testing recommendations:

• Run most tests on JVM
• Use native tests sparingly for specific scenarios
• Leverage buildpacks for CI/CD pipeline
• Test the real binary in staging environment

Library compatibility approaches:

• Use Spring Boot’s curated dependencies
• Check GraalVM reachability metadata repository
• Configure reflection manually if needed
• Encourage library maintainers to provide native configs

Production deployment considerations:

• Match build environment to target platform
• Consider using buildpacks for container images
• Monitor memory and startup time benefits
• Use JVMCI GC for throughput-critical applications