Enhancement of Vertical Scale Feature and merge in update API

Proposers

• Rahul Kumar (Tata Elxsi)
• Deepika E (Tata Elxsi)
• Jayaprakash G (Tata Elxsi)
• Ramesh Ramanathan (Tata Elxsi)

Description

This feature proposes to address the issue of flavor overriding during NS updates following vertical scaling operations in NS instances. This unexpected behavior results in the VNFD flavors taking precedence over potentially customized values used during the initial vertical scaling. This inconsistency can lead to unintended resource allocation and potentially disrupt service functionality.

We propose integrating the vertical scaling operation into the existing NS update API:

• API Endpoint: nslcm/v1/ns_instances/{nsInstanceId}/update
• New Update Type: "VERTICAL_SCALE"

The feature will address the technical debt from Release FIFTEEN, captured in the following bugs:

• https://osm.etsi.org/bugzilla/show_bug.cgi?id=2251
• https://osm.etsi.org/bugzilla/show_bug.cgi?id=2252
• https://osm.etsi.org/bugzilla/show_bug.cgi?id=2253

Demo or definition of done

Existing unit test/robot test will be updated, containing at least the following steps:

• Onboarding the NSD VNFD package.
• Instantiation of the NS and then after verifying successful NS creation.
• Trigger Vertical scale operation after changing the flavor in VNFD.
• VNFD's flavor should be updated in the instance running in VIM.