Fair Queue NF

[rohit-mp]

This PR adds a new example - Fair Queue with Round Robin Scheduler

The NF uses the advanced rings mode, classifies IPv4 packets based on the header information, and simulates a round-robin dequeue.

The CRC32 hash from the DPDK library has been used to classify the packets.

The NF uses a custom implementation of the standard FIFO queuing system. An implementation using the rte_ring structure from the DPDK library failed to scale for large number of queues.

Summary:

Usage:

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

Merging notes:

• Dependencies: None

TODO before merging :

• [ ] PR is ready for review

Test Plan:

An equal number of flows and queues are created to test the NF. The packets are generated by Pktgen and have same headers values except destination port with a 1000B packet size. An example:

A 1G NIC was used to send the packets to the NF. As can be seen from the image, each queue gets approximately 15MBps throughput which is 1/8th of the total link speed. A maximum of 35% hash collision probability is observed when the NF is tested with a large number of flows and queues (up to 1024).

NF Checklist:

• [x] Documentation describes purpose of NF, all arguments, and basic usage
• [x] NF stores all non-global state in a struct referenced by nf->data
• [x] NF performs initialization in a function_table->setup function and frees dynamic memory before exiting (NA)

Review:

(optional) << @-mention people who should review these changes >>

Subscribers: @mohittahiliani

[onvm]

In response to PR creation

CI Message

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[rohit-mp]

The code in the branch works fine as it is now as seen below

But upon interchanging the thread functionalities (i.e., applying this patch, the code seems to break as seen below

I was not able to figure out why this happens, and it would be great if I could get some help.

[rohit-mp]

Hi team, is there any update on this?

[bdevierno1]

Hi team, is there any update on this?

Hi @rohit-mp sorry for the delayed response. The team is looking at it now.

[catherinemeadows]

Hi @rohit-mp sorry for the delay and thanks so much for making this PR. When running the fair queue NF, I noticed two bugs:

1. When invalid arguments are used, the NF shuts down with a segmentation fault. To replicate this, try to run the fair queue NF as such: ./go.sh 1 -d. To fix this, in your destroy_fairqueue() function, you should check if (fairqueue == NULL) to handle the case that setup_fairqueue was never called in parse_app_args because -1 was returned in the case for no -d flag set
2. Regardless of the number of queues I specify, the manager always registers that I've started up two fair queue NFs with the same service ID but different instance IDs. Is there intention behind this and if so, what is the reasoning?

The below screenshot shows both happening.

[twood02]

@catherinemeadows - I think from our discussion earlier we decided that point 1 in your comment above is something we can easily fix ourselves and point 2 is expected behavior because this is based on the scaling API.

Other than that, was this ready to go?

[rohit-mp]

Thanks for the reviews and the fixes! Sorry I was preoccupied and wasn't able to allocate time to this.

[twood02]

Thanks for the contribution @rohit-mp !