Hi Peter, We use hot-deployment in production, to be able to update the application without losing all the sessions. But you have to configure Orion explicitly to keep the session state, as it is disabled by default. On the other hand, we also us it during development, but if you update the ear file very often, you usually ends up complaining with an OutOfMemoryException or some sort of decompression problems. So it is not very stable when used very often in a short period of time. That's why we try no to hot-deploy the ears in production very often, as it might cause a kaa-boum. I hope it helps, D.
Peter Beck wrote: > I tried to use the hot-deploy just for development to not always have to > restart Orion and log in. > To only have to restart the server when classes change which are stored > in the session would be better than on every little change during bug > fixing... > > On this list I read about people using this, and the problem they were > talking about most of the time was that classes have to be serializable... > Now I tried that with a few objects in the session, and all of them were > lost after touching application.xml. > > Peter > > Aaron Tavistock wrote: > >> I'm not currently doing hot-deploy, but I've always wonder how it could >> posibly work given that a serialized class might have the underlying base >> class changed during hot-deploy (e.g. the classic 'run instance' is >> different than a 'new instance' problem that java throws a >> ClassCastException from). Its also theoretically problematic (I'm not >> sure >> if instanceof or reflection will work properly). >> >> Since this is a very low-level issue (e.g. Java simply doesn't have the >> facilities to really handle this), how does hot-deply work? The only >> reliable strategy would appear to be to preserver primatives (since they >> don't change), maybe preserve 'well-defined' objects (java.util.* is >> unlikely to change), and discard all the rest. >> >> Any thoughts? >> AT >> >> -----Original Message----- >> From: Peter Beck [mailto:[EMAIL PROTECTED]] >> Sent: Tuesday, January 29, 2002 7:41 AM >> To: Orion-Interest >> Subject: hot redeployment - how to preserve session state? >> >> >> After a forced redeployment of an application on Orion 1.5.3 by >> touching application.xml >> my session state seemst to be completely lost. >> >> I have set development=true in my global-web-application.xml, and the >> switch is present in the orion-web.xml in the application- deployment >> directory. >> The variables I try to serialize implement the Serializable interface. >> Some of them are simple JavaBeans, others just Strings. >> >> For testing I use a JSP which prints the variables in the session. >> Before the redeployment everything is there. >> and when a user is logged in, request.getRemoteUser() gives me the >> correct user name. >> After the redeployment session.toString() still gives me the same ID >> as before, but all variables in the session are gone. >> Even request.getRemoteUser() == null. >> >> What am I missing? >> >> Peter
