I've got 4 web applications. They all have some specific code containing log statements but they also include a common "backend" codebase jar. Code in that common codebase also contains log statements. I want each of those 4 applications to have their own log file. That is, I want all log messages for webapp 1 to appear in webapp 1's log file, messages for webapp2 in webapp 2's file and so on. This is not a problem for the log statements appearing in the code specific to each webapp. But what about log statements in de common "backend" codebase (included by each of the webapps) ? How do those log statements "know" when log statements should go to webapp 1's logfile or webapp 2's log file ? Because that depends on where the calling thread initiated (in webapp1, 2, ...). I could augment each of my backend method signatures with a extra context parameter, but I hope there are more transparent solutions ? User => methodA Webapp1 => backend codebase methodX => webapp1.log User => methodB Webapp2 => backend codebase method => webapp2.log ... Any advice would be welcome. Thanks, EDH