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? (Long term: Policy should query an OOF microservice)
Last In First Out as a temporary solution? (Use in Dublin: will need to query for all instances and then choose)
Do we need to a preparation phase?
Use a generic Prep phase call that has a scaling flag that will trigger a pre scaling playbook
Do we need a post scaling phase?
Use a generic Post phase call that has a scaling flag to trigger a Post scaling playbook
In onboarding package vendor needs to say whether or not they support a Pre and Post action
How do we use Redistribute_Traffic?
How do we know when Redistibute is finished?
talk with Ops and use a MOPS type action to monitor the VNF to determine when Redistribute has finished.
Need to build a ConfigScaleIn action and API for APPC and SDNC