I found the problem. It's inside the commons-fileupload-1.1.1 library (or my wrong usage of it) which creates a leaking File-Object each time a HTTP-Request is parsed. See in DiskFileItem.java: public OutputStream getOutputStream() throws IOException { . if (dfos == null) { . . File outputFile = getTempFile(); . . dfos = new DeferredFileOutputStream(sizeThreshold, outputFile); . } . return dfos; } View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3972503#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...