How log framework helps reduce organize application logs instead of writing it from scratch

1. LOGS IN CODE
MODEN APPLICATION
Jannarong Wadthong
1/Sept/2020

2. ▸ Part I — Software Development and S.O.L.I.D ~ 10 mins
▸ Part II — Logs in Code ~ 30 mins
▸ Part III — Logs in Architecture ~ 15 mins
▸ Part IV — Log Framework ~ xx mins

3. SOFTWARE DEVELOPMENT
AND S.O.L.D
PART I

4. S.O.L.I.D

5. S.O.L.I.D

6. S.O.L.I.D

7. TEXT
MAINTAINABILITY CAN BE QUANTIFIED:
▸ Extensibility — how hard is it to add features
▸ Stability — how hard is it to make changes?
▸ Understandability — how hard is it for someone else to pick
up your code?

8. S.O.L.I.D

9. 12 PRINCIPLES BEHIND THE AGILE MANIFESTO

10. HOW TO AVOID TECHNICAL DEBT?
▸ Avoid code smells as you go, and practice regular
refactoring. Don’t Repeat Yourself (DRY), use clear &
consistent variable & method names, practice Test Driven
Development (TDD), follow the Single Responsibility
Principle (SRP), avoid long/complex methods, and
maintain thin interfaces / don’t hard-code
▸ Conduct code reviews.
▸ Use automated testing.

11. LOGS IN CODE
PART II

12. PUBLIC VS INTERNAL BANKING API
▸ Transfer Money API
▸ Deposit Money API
▸ Withdrawal Money API

13. TEXT
PUBLIC TRANSFER MONEY FLOW
CONTROLLER ACCEPTS
REQUEST
CONTROLLER ACK BACK TO USER
CHECK BALANCE WITHDRAW DEPOSIT
CHECK
AUTHORISATION

14. TEXT
INTERNAL TRANSFER MONEY FLOW
CONTROLLER ACCEPTS
REQUEST
CONTROLLER ACK BACK TO USER
CHECK BALANCE WITHDRAW DEPOSIT

15. INTERNAL TRANSFER
void transfer(Account fromAcc, Account toAcc, int amount) throws Exception {
if (fromAcc.getBalance() < amount)
throw new InsufficientFundsException();
fromAcc.withdraw(amount);
toAcc.deposit(amount);
}

16. PUBLIC TRANSFER
void transfer(Account fromAcc, Account toAcc, int amount, User user) throws Exception {
if (!isUserAuthorised(user, fromAcc)) {
logger.info("User has no permission.");
throw new UnauthorisedUserException();
}
if (fromAcc.getBalance() < amount) {
logger.info("Insufficient funds.");
throw new InsufficientFundsException();
}
fromAcc.withdraw(amount);
toAcc.deposit(amount);
}

17. PUBLIC TRANSFER WITH PERFORMANCE LOGGING
void transfer(Account fromAcc, Account toAcc, int amount, User user) throws Exception {
long startTime = currentTime();
if (!isUserAuthorised(user, fromAcc)) {
logger.info("User has no permission.");
throw new UnauthorisedUserException();
}
if (fromAcc.getBalance() < amount) {
logger.info("Insufficient funds.");
throw new InsufficientFundsException();
}
fromAcc.withdraw(amount);
toAcc.deposit(amount);
long endTime = currentTime();
logger.info("Execution time:" + (endTime - startTime);
}

18. S.O.L.I.D

19. S.O.L.I.D — HOW?

20. TEXT
WITHDRAW MONEY
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CHECK AUTHORISATION
CONTROLLER
CHECK BALANCE
DO WITHDRAW
START TIME
END TIME
START TIME
END TIME

21. TEXT
DEPOSIT MONEY
CONTROLLER
DO DEPOSIT
CHECK AUTHORISATION
CONTROLLER
DO DEPOSIT
START TIME
END TIME
START TIME
END TIME

22. TEXT
TRANSFER MONEY
CONTROLLER
CHECK BALANCE
WITHDRAW
CHECK AUTHORISATION
DEPOSIT
START TIME
END TIME
CONTROLLER
CHECK BALANCE
WITHDRAW
DEPOSIT
START TIME
END TIME

23. TEXT
WITHDRAW MONEY
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CHECK AUTHORISATION
CONTROLLER
CHECK BALANCE
DO WITHDRAW
START TIME
END TIME
START TIME
END TIME
DO WITHDRAW

24. TEXT
DEPOSIT MONEY
CONTROLLER
DO DEPOSIT
CHECK AUTHORISATION
CONTROLLER
DO DEPOSIT
START TIME
END TIME
START TIME
END TIME
DO DEPOSIT

25. ALL PUBLIC API
WITHDRAW
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
DO DEPOSIT
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
CHECK BALANCE
WITHDRAW
CHECK AUTHORISATION
DEPOSIT
START TIME
END TIME
DEPOSIT TRANSFER

26. ALL PUBLIC API
WITHDRAW
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
DO DEPOSIT
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
CHECK BALANCE
WITHDRAW
CHECK AUTHORISATION
DEPOSIT
START TIME
END TIME
DEPOSIT TRANSFER
PERFORMANCE LOGGING CONCERN

27. ALL PUBLIC API
WITHDRAW
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
DO DEPOSIT
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
CHECK BALANCE
WITHDRAW
CHECK AUTHORISATION
DEPOSIT
START TIME
END TIME
DEPOSIT TRANSFER
PERFORMANCE LOGGING CONCERN SECURITY CONCERN

28. PROBLEM HAVING LOGS IN CODE

29. PROBLEM HAVING LOGS IN CODE

30. PROBLEM HAVING LOGS IN CODE

31. PROBLEM HAVING LOGS IN CODE

32. CODE TANGLING AND CODE SCATTERING
WITHDRAW
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
DO DEPOSIT
CHECK AUTHORISATION
START TIME
END TIME
CONTROLLER
CHECK BALANCE
WITHDRAW
CHECK AUTHORISATION
DEPOSIT
START TIME
END TIME
DEPOSIT TRANSFER
PERFORMANCE LOGGING CONCERN SECURITY CONCERN

33. CODE TANGLING AND CODE SCATTERING
WITHDRAW
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CONTROLLER
CHECK BALANCE
DO WITHDRAW
CONTROLLER
DO DEPOSIT
CONTROLLER
CHECK BALANCE
WITHDRAW
DEPOSIT
DEPOSIT TRANSFER
PERFORMANCE LOGGING ASPECT SECURITY ASPECT

34. WE WANT THIS
@LogExecutionTime
@Authorize
void transfer(Account fromAcc, Account toAcc, int amount, User user) throws Exception {
checkBalance(fromAcc);
fromAcc.withdraw(amount);
toAcc.deposit(amount);
}

35. TEXT
AOP IMPLEMENTATION: DYNAMIC PROXY
@Aspect
Performance Logging Proxy
1.start time
2.end time
ATMController Target Service
+ transfer()
+ withdraw()
+ deposit()
As you can see from that diagram, the proxy has one job.
• Opening and closing times.
• And then delegating to the real target service, the one we wrote.
• And ATMController will never know that they are talking to a proxy, and not the real thing.
2 MARKERS: @BEFORE AND @AFTER
OR 1 MARKER: @AROUND

36. TEXT
AOP IMPLEMENTATION
@Aspect
Authorisation Proxy
1.check if user is valid
ATMController Real ATMService
+ transfer()
+ withdraw()
+ deposit()
1 MARKER: @BEFORE

37. TEXT
ASPECT
@Aspect
public class PerformanceAspect {
@Around("@annotation(LogExecutionTime)")
public Object logExecutionTime(ProceedingJoinPoint joinPoint) throws Throwable {
long start = System.currentTimeMillis();
Object proceed = joinPoint.proceed();
long executionTime = System.currentTimeMillis() - start;
log.info(joinPoint.getSignature() + " executed in " + executionTime + "ms");
return proceed;
}
}

38. LOGS IN ARCHITECTURE
PART III

39. This slide is intentionally left blank :)

40. TEXT
LOGS IN ACTION
▸ Troubleshooting
▸ Law
▸ User behaviours

41. TEXT
PUBLIC TRANSFER MONEY FLOW

42. TEXT
LOG FRAMEWORK: IMPLEMENTATION
LOG
HARDDISK
STOUT REST API
DATABASE
TEXT FILE
PROMETHEUS GRAFANA

43. TEXT

44. TEXT

45. TEXT

46. SUMMARY
Begin/End Transaction
Transaction Error Hand

47. TEXT
THANK YOU