Scaling Example NF Updates

[catherinemeadows]

Modified the Scaling Example NF to assign spawned children with the same service ID as the parent and updated the README with more detail about callback and advanced rings modes.

• addressed issue 250

Summary:

Usage:

This PR includes
Resolves issues	250
Breaking API changes
Internal API changes
Usability improvements
Bug fixes
New functionality
New NF/onvm_mgr args
Changes to starting NFs
Dependency updates
Web stats updates

Merging notes:

• Dependencies: None

TODO before merging :

• [X] PR is ready for review

Test Plan:

• tested NF in a chain (speed tester -> scaling -> basic monitor) to verify correct packet flow

[twood02]

@catherinemeadows Can you remind me -- Is the idea of this NF that it spawns N child NFs all with the same service ID as the "main" NF that started initially. Packets are then distributed across the N+1 NFs. All of these NFs then forward packets to whatever destination ID was set on the command line.

Is this right? Or does the main NF not actually have a run loop so there are N nfs total receiving packets (only the children)?

[catherinemeadows]

@twood02 Yes, the parent NF spawns N children NFs with the same service ID and the packets are distributed across the N+1 NFs and forwarded to the destination ID. Should I add this to the documentation?

[twood02]

@NoahChinitzGWU can you build and run this code on one of your systems to verify it is working as expected? Post a screenshot/paste the output here

[NoahChinitz]

Manager:

Scaling NF Left Terminal, Monitor NF Right Terminal:

Does this seem correct, or should I be seeing 3 additional scaling NFs in the manager?

[catherinemeadows]

They should scale once you send packets to it (you can use speed tester)

[NoahChinitz]

Manager:

Works!

[NoahChinitz]

NFs used (scaling left, basic monitor middle, speed tester right)

[twood02]

@dennisafa - can you do a very quick review and approve this if nothing jumps out at you?