程序登录到控制台时会发生什么？

Question

I have a java server application running that uses Logback as its primary logging library. Recently I asked a developer to remove the extra console logging they had added for a non-development environment and when they asked me why realized I didn't have solid reasoning for it.

The extra logging I believe would cause more I/O operations but does it also add more memory usage? How large is the buffer that it's writing to in stdout and when is that cleared?

Our standard logging is to a file which we can view or also have it piped into monitoring tools. The application is deployed via an automated process and is headless so generally no one is on the VM looking at things.

Example logging appenders ( Dropwizard configurations )

logging:
  level: INFO
  appenders:
    - type: file
      currentLogFilename: /var/log/myapplication.log
      archive: true
      archivedFileCount: 5
    - type: console
      target: stdout

Essentially, is there a detriment to logging to the console when not using it and what does that take the form of?

Answer 1

Unless you are logging millions of records, logging has no noticeable impact on performance.

Logging to the console is more ephemeral than logging to a file--the log messages are not saved anywhere. This makes it impossible to track down errors and troubleshoot problems, especially in production.

Answer 2

Logging to STDOUT can be useful if you run your application inside a container like Docker. Docker can fetch anything written to STDOUT and STDERR in any container it runs using docker logs or can redirect to a different server. If the application would write to a logfile local to the container it runs it, it would be much more difficult to access this file from outside the container.