What's the best practice for hot-redeployment of WARs to Tomcat? Say that I have a webapp that serves a long-running type of user (logs in in the morning, uses all say), and want non-stop redeployment of the app where the current users can continue to be logged in but new sessions gets created against a redeploy war. My best guess would be using a loadbalancer and two sets of Tomcat instances, but whats the best practice and best software to do this (current environment is based on Ubuntu, Tomcat and Nginx.
Use Tomcat 7's hot deployment, in which your updated app runs alongside the current version. New sessions will use the new version, established sessions will use the current version. However, keep in mind that most security best practices want you to disable hot deployment.