Edge Cache and CDN Platform · View 07 of 29 · 3 · Structure
Decisions
- PoP autonomy is its own layer. The agent, the local log mirror and the last five signed bundles are what let a PoP serve for weeks without the control plane.
- Keyspec is drawn as a decision, not a component. It is small, it decides whether a stored response may answer a request, and it is the most carefully tested code on the platform.
- The tag table sits in the serving layer because every lookup reads it. It is written from below by the agent and never by the request path.
The rule these arrows follow
- Serving depends on local disk. Local disk is filled from the control plane. The control plane writes records. No arrow points up, so the failure of any lower layer beyond the PoP stops change, never delivery.
Omitted
- Identity, key custody and paging are cross-cutting and are drawn on views 27 and 28.
