禁用剂量的logger.debug是否会影响性能？

Question

I use log4j in my application. In development I use tons of logger.debug to display infomation for debugging. I know I can make these verbose displays go away by changing the logging level in the configuration file when deployed, my questions is will this affect performance? Is it that although the debug level is disabled, the logging work is still there and dose something silently? Is it better to remove all the logger.debug codes in the final deploy version if performance is important?

Answer 1

Modern loggers very quickly return from an inactive logging statement for this very reason

You need to be aware of the price of constructing the string to be logged. If you use slf4j as the front end, use {} to delay this until after the tests

Answer 2

Any IO operation will affect performance. Even if you change logging level, each time you call log.debug , logger have to make decision to print message or not. However, making decision is faster than doing it with writing to file/console/something else.