I'd have to say 98% of my app is stateless, I only have a few admin pages that still use tapestry grid. Other than that Captcha and Tapestry Security redirect seem to be the only two items effected by this, so I don't think I'll have a memory issue.
Kalle, I still use AWS and thus far it's been very reasonable. I just worry instances being held active and running my bill up because of sticky sessions. I'll admit, I'm no expert in this, so perhaps my understanding isn't correct. Is there any recommendation for the timeout? I currently have it set at 0. On Thu, Dec 4, 2014 at 1:26 PM, Kalle Korhonen <kalle.o.korho...@gmail.com> wrote: > On Thu, Dec 4, 2014 at 5:54 AM, George Christman <gchrist...@cardaddy.com> > wrote: > > > Hi guys, so I've had a slew of strange behaviors over the past few months > > with a few different Tapestry components such as Tapestry Grid, Tapestry > > Captcha, and writting/removing cookies. Last night I was finally able to > > fix them, but at the cost of a sticky session. My application sits > behind a > > load balancer, so my question is why do I need to use a sticky session > and > > how do I avoid the use of them? I'm concerned with the fact this is going > > to cause a scaling dilemma. > > > > I'd almost say that sticky sessions are more the norm than the exception > for Java web applications. Unless you change your implementation, you have > a choice between sticky sessions or replicated/centeralized sessions. > Sessions in your cluster are probably not managed by memcached or some such > (which is another single point of failure), causing the strange behavior. > Furthermore, I see neither session usage nor sticky sessions as inherently > bad. Memory is cheap although in today's cloud managed solutions using > memory may end up costing extra to you. It depends on how your load > balancer works and whether the bottleneck in a typical usage pattern is cpu > or memory. Even if your load balancer does a simple random choice but > memory doesn't cost you, you are most likely fine with sticky sessions. If > additional servers cost you, but you can do dynamic horizontal scaling with > cpu/memory thresholds to spawn new instances, then sticky sessions are > actually desirable. > > Kalle > > PS. @Alex - yes, can configure default persistence strategy with > @Meta("tapestry.persistence-strategy=client") per page - but that only > works if the components don't require an explicit persistence strategy > -- George Christman CEO www.CarDaddy.com P.O. Box 735 Johnstown, New York