I have a web service application which uses logback version 1.0.0.jar with debug enabled in Test region. Attached is the log back version that we are using in this application. The response time of the webservice application is reduced by 100ms-200ms under exactly same situation when we removed the [%file:%line] from the pattern tag in the logback.xml

General response time (with attached logback.xml) :300ms (averaged -Under same situations)
After removing [%file:%line] from the pattern response time is: 120-150ms(Under same situations)