I've managed to solve this by placing the key into the application session, not portlet session so all portlets would share the same DnDCache. Here's the code: public static DnDCache getInstance(FacesContext context, boolean encoding) {         PortletSession portletSession = (PortletSession)context.getExternalContext().getSession(false);         DnDCache cache = (DnDCache) portletSession.getAttribute(SESSION_KEY,PortletSession.APPLICATION_SCOPE);         if (cache == null) {             cache = new DnDCache();             portletSession.setAttribute(SESSION_KEY, cache, PortletSession.APPLICATION_SCOPE);         }         return cache;     } However, this code is not yet standardized to your current structure to use portal context detection, so if you run this in a servlet environment it would not work. It would be nice if you could look into it and if you consider it's a good solution, make the necessary adjustments or comments on my ideea. Thanks,     Dan Leahu.