It seems like all the node woker processes are working as if it is executing a new copy of the same application. But would like to keep some variables that are shared by all nod
All worker processes are indeed new copies of your application. Each worker is a full featured process created with child_process.spawn. So no, they don't share variables. And it's probably best this way. If you want to share information between worker processes (typically sessions) you should look into storing these information in a database.
If you're ready to go node all the way, you could use something like dnode to have your workers ask the master process for data.