Step-1: In “Runtime Environment” (here for Tomcat) - JRE must be mapped to the same JRE of JDK in which DCEVM is patched (look at quick start how to setup DCEVM).
Step-2: Add “-XXaltjvm=dcevm -javaagent:
Step-3: If you use servlet container like Tomcat, JBoss, Glassfish etc., disable option Auto Reload (in web modules). This is most important step, otherwise you will not see power of Hotswap Agent in step-4.
Step-4: Run your application or servlet container (Tomcat, JBoss, Glassfish …) in Debug mode and enjoy java coding. When you start your server in debug mode, you should see messages like below in Eclipse Console.
Now if you do code changes in Java as well as configuration files of supported plugins (i.e. logback.xml), those would be updated without server restart.