On 27/02/2012 22:23, Aristedes Maniatis wrote: > On 28/02/12 12:14 AM, Christopher Schultz wrote: > Chuck, > > On 2/26/12 11:29 PM, Caldarale, Charles R wrote: >>>>> From: Aristedes Maniatis [mailto:amania...@apache.org] Subject: >>>>> Re: parallel deployment: multiple applications responding >>>> >>>>> What happens if our application defines a static class or other >>>>> resource? >>>> >>>> Not sure what you mean by "static class", unless you're referring >>>> to an inner class. Regardless, each parallel deployment uses a >>>> separate classloader, so the webapp instances cannot interfere >>>> with each other. > > I'm sure he means a class with a static method that returns a shared > object (aka singleton, etc.). > >> Yes of course. I mispoke earlier. > > >>>> However, if you've placed classes in a shared library (e.g., >>>> Tomcat's lib directory), anything in there will be shared by all >>>> webapps. You must be very, very careful when utilizing shared >>>> classes, since that can easily lead to unexpected data leakage >>>> between webapps (not to mention often making it impossible to >>>> undeploy them). > > Yes, but I would be very surprised if one could cause a different > webapp to service a request by doing such a thing. What you might be > able to do is get the request *logged* to the wrong webapp, if you > were fetching references (say, to the ServletContext) and caching them > in the (shared) class, then calling ServletContext.log on them. > > Aristedes, can you describe in a bit more detail the kinds of things > you are doing, here? > > Also, what kind of logging are you using that suggests your requests > are being handled by the wrong webapp? What does JMX have to say about > the number of active sessions? (You said that the 'manager' webapp > shows a status for the webapp, so you are probably using that session > count in your reports, here, but I just wanted to check). > > >> I'll focus on trying to get some better logging of the session into the >> log output and see if we can narrow down the symptoms. Yes, I am using >> JMX and the Manager app to identify when there are no remaining >> sessions, and when I therefore should expect to see no further activity >> at all from the older application. I'll try and get some better >> information around that by adding logging as you suggest. > >> The logging that we did originally to discover this problem was simple: > >> * sessionless application >> * we changed the log.properties for log4j in the new app >> * some hours after we deployed, the old-style log entries were still >> being written, mixed in with the new ones
Aristedes, Did you manage to resolve the problem or narrow down on what is actually happening? p
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