- Covenant Ko is a founder and maintainer of the Github organization 'brave-people' and has a technical blog that has received over 410,000 visits - He explains Anderson's Formula for calculating expected value, which takes into account probability of success (P) and payoff for success (S) - Some tips he provides include making the common case fast, using static fields for caches but not databases, and that StringBuffer is thread-safe while StringBuilder is not

1. Covenant Ko
Part 1
11

2. - Name. Covenant Ko
- Company. 11번가
- Github 용감한친구들 Organization Founder & Maintainer. https://github.com/brave-people
- Github. https://github.com/KoEonYack
- Tech Blog. https://covenant.tistory.com/ (누적 방문 41만)

3. https://d2.naver.com/helloworld/1329

4. https://www.tuning-java.com/521?category=71583
10,000 ,
, .(NHN .
NHN . ^^)

5. +
(P: , S: )
https://ko.wikipedia.org/wiki/%EC%95%94%EB%8B%AC%EC%9D%98_%EB%B2%95%EC%B9%99

6. 100%(P=1)
2 (S=2)
+
(P: , S: )
https://ko.wikipedia.org/wiki/%EC%95%94%EB%8B%AC%EC%9D%98_%EB%B2%95%EC%B9%99
1
(1 ‒ 1) +
1
2
= 2

7. 90% (P=0.9)
2 (S=2)
+
(P: , S: )
https://ko.wikipedia.org/wiki/%EC%95%94%EB%8B%AC%EC%9D%98_%EB%B2%95%EC%B9%99
1
(1 ‒ 0.9) +
0.9
2
= 1.8

8. (P: , S: )
https://ko.wikipedia.org/wiki/%EC%95%94%EB%8B%AC%EC%9D%98_%EB%B2%95%EC%B9%99

9. (P: , S: )
https://ko.wikipedia.org/wiki/%EC%95%94%EB%8B%AC%EC%9D%98_%EB%B2%95%EC%B9%99
1. .
2. .
3. (Make the common case fast)
4.

11. https://d2.naver.com/helloworld/6070967

12. APM JENNIFER
(Java EE, .NET, PHP) APM(Application Performance Monitoring)

13. APM scouter

14. watab
https://youtu.be/QYEvHvbX-8E

15. https://www.jrebel.com/blog

16. vs APM
APM
1.
2.
3. ,
4. APM
5.
21p

17. vs APM
APM
1.
2.
3. ,
4. APM
5.
1.
2.
3.
4. CPU
21p

18. vs APM
APM

19. 01 String StringBuffer, StringBuilder
1.
2. JDK 1.5 String +
2. Thread Safe or Thread Safe ( )

20. 02 static
Static GC ?

21. 02 static
https://syundev.tistory.com/222
https://yaboong.github.io/java/2018/06/09/java-garbage-collection/

22. 02 static
static
static
1. static final
2. static
3. DB (But Cache )
1. Thread safe 상황
2. .

23. 1.
2. (Make the common case fast)
3. Java
4.

24. Covenant Ko