Any way to get number of active sessions

Question

Hi,
          With the deprecation of the HttpSessionContext interface as of Servlet API
          2.1 for security reasons, is there any way to know how many sessions are
          currently active in a given WebLogic instance?
          Thanks,
          Sanjiv
          

Answer 1

You could make it a singleton. The overhead is nothing ... trust me. Run
          WebLogic through a profiler if you don't ;-)
          Good luck,
          Cameron Purdy, LiveWater
          "Sanjiv Gulati" <[email protected]> wrote in message
          news:[email protected]...
          > Thanks for sharing this technique. Although I haven't used the
          > HttpSessionBindingListener interface myself, this will work as long as I
          add
          > an instance of SessionCounter in each new session. The only modifications
          > I'll add to the code below would be a synchronized block within the
          > valueBound and valueUnbound methods so that modifications to m_cSessions
          are
          > thread safe.
          >
          > The overhead associated with this approach will be the following:
          > 1) For every session there will be an associated SessionCounter, and
          > 2) Serialization of requests that end up invoking the valueBound &
          > valueUnbound methods.
          >
          > But I guess this cannot be avoided.
          >
          > Thanks,
          > Sanjiv
          >
          > Cameron Purdy <[email protected]> wrote in message
          > news:[email protected]...
          > > The only portable implementation is to have all requests go through your
          > > servlet code (or JSP code) and check if the session is new
          > > (HttpSession.isNew). If so, register a value with the session that
          > > implements HttpSessionBindingListener. Something like:
          > >
          > > class SessionCounter implements HttpSessionBindingListener {
          > > // count of active sessions
          > > private static int m_cSessions;
          > > // accessor for count of active sessions
          > > public int getSessionCount() {
          > > return m_cSessions;
          > > }
          > > // this object placed on a session
          > > void valueBound(...) {
          > > ++m_cSessions;
          > > }
          > > // this object removed from a session
          > > void valueUnound(...) {
          > > --m_cSessions;
          > > }
          > > // end class
          > > }
          > >
          > > It is host-local ... meaning it only tracks one host in a cluster.
          > > Actually, it only tracks sessions within one classloader on one host in
          a
          > > cluster, but don't worry about that distinction.
          > >
          > > And no, I've never done it, but it is apparent that you could, if you
          > chose
          > > to:
          > >
          > > 1) Count sessions
          > > 2) Track all session instances
          > > 3) Have session-level events, such as onCreate/onDestroy
          > >
          > > Hope it helps,
          > >
          > > Cameron Purdy, LiveWater
          > >
          > > "Sanjiv Gulati" <[email protected]> wrote in message
          > > news:[email protected]...
          > > > Hi,
          > > >
          > > > With the deprecation of the HttpSessionContext interface as of Servlet
          > API
          > > > 2.1 for security reasons, is there any way to know how many sessions
          are
          > > > currently active in a given WebLogic instance?
          > > >
          > > > Thanks,
          > > > Sanjiv
          > > >
          > > >
          > >
          > >
          >
          >