Question

I never bothered to find this out. Let’s see I have a java web application running called “myapp” What’s the difference between myapp.out and myapp.log file?

.log file can be rotated according to log4j.properties setting, how about .out file? do I need to set up the rotation policy for it as well?

Answer 1

The difference between .log and .out is the last three letters of the file name. Log4j and System.out can be redirected to either of them. if you are using log4j properly you should get much if any output to System.out so you shouldn’t need to rotate it.

If your application doesn’t use log4j particularly well and writes alot to System.out, you may need to rotate the file, but this will require you to restart the application.