This session will include the following subject(s):
Using notifications:
Instead of polling backend APIs to get an updated status of a resource, Heat should subscribe to notifications when they exist, and simply wait for the relevant information to show up.
We could start by moving the nova server creation.
Topics to discuss: * Implementation strategy: Do we have a separate process subscribing to the broker? Do we subscribe to all the messages and filter afterwards? * Do we keep the current polling system as a backward compatible mechanism? * Race conditions * Timeouts