This document discusses optimizing Spring Boot applications. It explains that @SpringBootApplication combines configuration, component scanning, and auto-configuration annotations. It also explores JVM optimizations like tiered compilation and class data sharing to improve startup performance in Spring Boot applications. Class data sharing, in particular, can reduce startup time by caching class metadata between JVM launches.

1. Spring Boot Application
(@mike_neck)

2. 1
@SpringBootApplication

3. Spring Boot
! @SpringBootApplication

5. @Configuration @Import
@Bean

6. @SpringBootApplication
@Import @Bean
• @SpringBootApplication @EnableAutoConfiguration @ComponentScan
• @EnableAutoConfiguration AutoConfigurationImportSelector META-
INF/spring.factories Configuration
• @ComponentScan @Component
@Bean
• Configuration/Component
• Configuration @Import @Component
@Bean
• spring.autoconfigure.exclude

7. https://qiita.com/kazuki43zoo/items/
8645d9765edd11c6f1dd

8. @SpringBootApplication
6.206 sec 5.811 sec
1 6.366 sec 5.975 sec
2 6.180 sec 5.817 sec
3 6.071 sec 5.642 sec

9. 2
JVM

10. JVM
• -XX:+TieredCompilation
• (Java8 )
• -XX:TieredStopAtLevel=1
• 1( +
)
• -noverify
•

12. JVM
JVM
6.866 sec
-XX:+TieredCompilation 5.963 sec
-XX:+TieredCompilation
-XX:TieredStopAtLevel=1 4.493 sec
-XX:+TieredCompilation
-XX:TieredStopAtLevel=1
-noverify
3.709 sec

13. 3
Class Data Sharing
JVM

14. Class Data Sharing
(CDS)
• Java8 Java 10 OpenJDK
• JVM JVM /
• !
•
•
•

15. https://qiita.com/ykubota/items/
664032c14f992e04cde2

16. CDS
CDS CDS
6.206 sec 6.571 sec
1 6.366 sec 6.503 sec
2 6.180 sec 6.893 sec
3 6.071 sec 6.319 sec

18. Spring Boot Jar
( )
• bootJar Launcher jar
• JarLauncher BOOT-
INF/ /
• bootJar jar
Spring/ jar java -cp

19. Class Data Sharing
※ Web
bootJar
CDS
java -cp …
CDS
java -cp …
CDS
12.21 sec 10.79 sec 7.663 sec
1 12.84 sec 10.46 sec 7.455 sec
2 11.81 sec 10.28 sec 7.861 sec
3 11.97 sec 11.64 sec 7.673 sec

20. CDS
•
•
bootJar (6.2sec -> 6.7sec)
•SpringCGLIB ( )
•
•-jar bootJar jar -cp

21. • @SpringBootApplication @Import
@Bean
•
• Class Data Sharing
• bootJar jar -cp

22. •
• twitter: @mike_neck
• L is B
Java
• 5/26( ) JJUG CCC 2018 Spring ( )
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