Load balanced cells
In some situations the nova-cell process can become a bottle neck and not consume messages from the RPC system fast enough.
This blueprint sets out to enable multiple 'nova-cell' consumers from a single RPC queue.
It should work all scenarios, for example:
- Global cell
- nova-api instances put messages in the queue, multiple nova-cell instances push those messages down to child cells
- Child cell
- incoming command messages come from a parent cell into our RPC queue, multiple 'nova-cell' workers consume and process these messages.