State Sharing

[brianehlert]

Overview

As a user of NGINX Ingress Controller, I would like to ensure that all of my pods are aware of each-others state to ensure constant behaviour when configuring policies such as Rate Limiting

High-level Functional Requirements

• Provide users with a means to enable and configure state sharing

Definition of Done

Development

• Unit tests are written to cover functionality delivered in the story.
• Make sure that the unit test passes before creating a pull request.
• Make sure that the test coverage stays optimal.
• Run make lint locally before creating a PR.

Testing

• Automated tests are written as part of the story.
• Run “make lint-python“ from root
• Acceptance criteria are met.
• Stories are demonstrated to the team.
• Product Manager accepts the story as done.
• If a feature requires changes/extensions of the Helm chart, those shall be done as part of the story.

Release Notes & Documentation

• PR is labeled appropriately so they display in GitHub release notes.

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References

Guide on "cluster" ratelimiting (mentions zone_sync and zone for different contexts)

https://www.f5.com/company/blog/nginx/nginx-plus-r16-released#r16-cluster-rate-limiting

NGINX Admin guide on zone_sync for state sharing

https://docs.nginx.com/nginx/admin-guide/high-availability/zone_sync_details/

NGINX stick directive for upstreams

https://nginx.org/en/docs/http/ngx_http_upstream_module.html#sticky

What is zone_sync?

The ngx_stream_zone_sync_module module (1.13. 8) provides the necessary support for synchronizing contents of shared memory zones between nodes of a cluster