Starting from uWSGI 1.5-dev a new subsystem for clustering has been added: The Legion subsystem.
A Legion is a group of uWSGI nodes constantly fighting for domination.
Each node has a valor (different from the others).
The node with the higher valor is the Lord of the Legion (or if you like a more engineer-friendly term: the master)
This constant fight generates 4 kind of events: start of the fight (setup), end of the fight (death), becoming a lord (lord), loosing the lord title (unlord).
You can trigger actions every time such an event rises, and this should switch-on the light on your brain.
An example, as always is the best approach for learning:
This is probably the king of all of the example, as this is a very common needs in clustered environments.
The ip address is a resource that must be owned by only one node (i suppose you know what could happens otherwise...).
That node is our Lord.
If we configure a Legion right (remember, a single uWSGI instances can be a member of all of the legions you need) we could easily implement ip takeover.