After every WAR file redeploy (Tomcat 8) a new file handle/descriptor to the current log file will be created. The undeploy of the old WAR file will not close/release the open file handle/descriptor to the current log file. Therefore, the number of file handles/descriptors to the current log file increases with every WAR file redeploy. Unfortunately, logback cannot role a log file with 2 or more open file handles/descriptors -> the RollingFileAppender is not working anymore.

Why logback does not close/release the file handle/descriptor to the current log file when a WAR file was undeployed?

Stopping the logging context by hand is odd.