CFP: Active Connection Tracking

[AwesomePatrol]

Cilium Feature Proposal

Active Connection Tracking

This proposal was presented during Cilium Developer Summit on 18 March, 2024.

Is your proposed feature related to a problem?

"Advanced" L4 load balancers can't make informed decisions on load distribution between the zones without information that could approximate L7 concept of a request.

This is a prerequisite for further xDS control-plane integration.

Describe the feature you'd like

Track number of active and new connections to each service grouped by the backend's zone.

Describe your proposed solution

More details in the design doc

This proposal will consist of the following stages:

• [x] Passing zone information from EndpointSlices to lb{4,6}_backend
• [ ] Updating counters in cilium_lb_lrs BPF map (make it available only with cilium map get cilium_lb_lrs)
• [x] Adding way to configure zone ID<->name mapping
• [ ] Surfacing this information in /metrics