From what I can tell from you're question, you want a load balancer in front of your application servers, i.e. a single point of entry that will direct requests to an application server, while being smart enough not to direct to a server in the process of re-deploying the application. If you use mod_cluster for load balancing, then you'll be able to retain availability during hot re-deployment. You'll want to make sure your application is configured with distributed web sessions and clustered SFSBs (if needed). See the docs for details:
If that wasn't the essence of your inquiry, please restate your question.
Thanks Paul for your answer.
Yes, I'll use httpd with mod_cluster in the front.
Let's suppose that I have two nodes running in farm mode: I want to make a hot deploy with farm, both nodes will redeploy at the same time, so the application would be offline a few minutes until one node is available, right?
I cant allow that, I need to have one node available.
An option is to not use farm, and deploy each node manually: deploy node1, wait to see it restarted, then deploy node2, etc.
My question is, can farm do this "secuential deployment" for me?