Include the URL of your launchpad blueprint:
The convergence design requires extra data to be stored with each Stack row in order to manage concurrent updates.
Add the following extra fields to the Stack table:
We also need to ensure that modifications to the Stack table are atomic with respect to the current_traversal field - if a new traversal starts then any previous traversals should stop updating the stack data. This should be achieved using the “UPDATE ... WHERE ...” form as discussed in http://www.joinfu.com/2015/01/understanding-reservations-concurrency-locking-in-nova/