Well, I did it, and it was too easy. Adding a line in SessionInterceptor.beforeBody(): response.addHeader("jsessid", (reqSessionId!=null) ? reqSessionId : rrequest.getRequestedSessionId() ); And in httpd.conf: LogFormat "%h %l %{jsessid}o %t \"%r\" %>s %b" toppkcommon Wow... too simple... now I need the program to interprete the info ;) Thanks tomcat crew, thanks apache crew, Kenneth