In Dublin our primary reason for scaling will be focused on adjusting resources to the load. As load increases or decreases, the VNF will scale Out or In as appropriate. This can be done either manually or automatically.
Other reasons for scaling may include:
Upgrades
VM Moves
Meet with Operations to determine other reasons
Which instance should be removed?
Is this an Optimization decision?
How should Policy be involved?
Last In First Out as a temporary solution?
Do we need to a preparation phase?
Possible items to be checked in a preparation phase:
Upgrade and rollback for both VNF and RAP
Snapshot Saving
Another ongoing scaling operation
Syncronization problems between VNFM and VNF database
DB Service Status
Do we need a post scaling phase?
Do we need additional configuration changes after VM removal?
How do we use Redistribute_Traffic?
How do we know when Redistibute is finished?
Need to build a ConfigScaleIn action and API for APPC and SDNC