The document discusses the optimizations Quarkus makes compared to traditional Java frameworks, focusing on performance, startup time, and memory footprint. It highlights Quarkus's ability to halve resource usage and significantly increase boot speed through its unique build processes and extension mechanisms. The document also explores how Quarkus streamlines application startup by modifying class paths and utilizing tools like GraalVM for native image compilation.

1. DATE OR VENUE
Quarkus Application Bootstrap
where do small sizes and timings
come from?
JAVA MARATHON – JULY 2020

2. WHOAMI
mgovorischev maksym_govorischev
mgovorischev@gmail.com

3. New player - Quarkus

4. WHY?

5. What is wrong with Java frameworks
• They load too many classes
• They perform a lot of initialization at runtime
• They overuse dynamic/reflective functionality (in general
and during startup in particular)
• They need to be paired with full-fledged JVM to run

6. WHAT?

7. What is being optimized?
• Performance – startup time

8. Performance – startup time
https://dzone.com/articles/micr
oservices-quarkus-vs-spring-boot

9. What is being optimized?
• Performance – startup time
• Resources – memory footprint (RSS)

10. Performance – memory footprint
https://dzone.com/articles/micr
oservices-quarkus-vs-spring-boot

11. How faster/smaller? Rule of thumb
Hotspot optimized Quarkus App
½ the RSS space
X5 boot speed
Native optimized Quarkus App
1/5 the RSS space
X50 boot speed
@Dimitris Andreadis, Director of Engineering at Red Hat

12. What is being optimized?
• Performance – startup time
• Resources – memory footprint (RSS)
• Resources – app size

13. Why app size matters? Because of lambdas

14. WHEN?

15. How does usual Java framework start?

16. How does usual Java framework start?
Packaging (maven, gradle)

17. How does usual Java framework start?
Packaging (maven, gradle)
Load and parse
config files

18. How does usual Java framework start?
Packaging (maven, gradle)
Load and parse
config files
Classpath scanning
and annotation
discovery. Enable
features based on
class availability

19. How does usual Java framework start?
Packaging (maven, gradle)
Load and parse
config files
Classpath scanning
and annotation
discovery. Enable
features based on
class availability
Build metamodel
of the world

20. How does usual Java framework start?
Packaging (maven, gradle)
Load and parse
config files
Classpath scanning
and annotation
discovery. Enable
features based on
class availability
Build metamodel
of the world
IO, threadpools, etc

21. How does usual Java framework start?
Packaging (maven, gradle)
Load and parse
config files
Classpath scanning
and annotation
discovery. Enable
features based on
class availability
Build metamodel
of the world
IO, threadpools, etc
Build time

22. How does usual Java framework start?
Packaging (maven, gradle)
Load and parse
config files
Classpath scanning
and annotation
discovery. Enable
features based on
class availability
Build metamodel
of the world
IO, threadpools, etc
Build time Runtime

23. How does Quarkus start?
Packaging (maven, gradle)Load and parse
config files
Classpath scanning
and annotation
discovery. Enable
features based on
class availability
Build metamodel
of the world
IO, threadpools, etc
Build time Runtime

24. HOW?

25. Quarkus build paths
*.class

26. Quarkus build paths
*.class
Maven/Gradle plugin

27. Quarkus build paths
*.class
Maven/Gradle plugin
Optimized Jar
Extensions

28. Extensions mechanism
Extensions
Class-path
modification
Build
augmentation
Build Steps

29. Build Step

30. Extensions mechanism
Extensions
Class-path
modification
Build
augmentation
Build Steps Build Items

31. Build Item

32. Extensions mechanism
Extensions
Class-path
modification
Build
augmentation
Build Steps Build Items
Bytecode
recorders

33. Recorder
[ STATIC_INIT |RUNTIME_INIT ]

34. Tools under the hood
Jandex

35. Tools under the hood
Gizmo
Jandex

36. Build Augmentation
Index
Corequarkus-data
Parse
Config
Step
Scan
Step
Repo
Init
Step
app.properties
Application.class
Static Init
Runtime Init
Recorded
bytecode
ApplicationIndexBuildItem
ConfigBuildItem
- Build item - Build step

37. Quarkus build paths
*.class
Maven/Gradle plugin
Optimized Jar
Jlink + AppCDS
Extensions

38. Quarkus build paths
*.class
Maven/Gradle plugin
Optimized Jar Native
executable/image
Jlink + AppCDS
Extensions

39. Tools under the hood
Graal Compiler
Gizmo
SubstrateVM
Jandex

40. GraalVM

41. AOT Native Image Compilation with GraalVM

42. Extensions mechanism
Extensions
Class-path
modification
Build
augmentation
Build Steps Build Items
SubstrateVM
Substitutions
Bytecode
recorders