I've read about asynchronous HTTP and REST and how can you return a resource after POST-ing to initiate a long running task and then polling that resource to get the task's status.
I wonder what happens if I have two machines that are load-balanced and one will receive the initial POST and the other a subsequent GET. The second will not be aware of what the first one started, unless I use a common storage to keep the task's state.
How can I prevent that if I want to keep the state only on the client?