Stateful information sync for ext-proc Instances

[Jeffwan]

🚀 Feature Description and Motivation

Our external process in the Envoy Gateway tracks request routing using prefix cache awareness, making it stateful. To ensure consistency and availability across multiple instances, we need to design a state synchronization mechanism.

• Current ext-proc builds a hash blocks/radix tree to track requests.
• Multiple instances need to share this prefix cache state and avoid data inconsistencies between instances.
• Ensuring minimal performance impact while syncing state.

external distributed store/election/event-driven sync etc seems a little bit heavy. We need to consider the lightweight approach for implementation.

Use Case

unblock prefix-cache awareness request scheduling in HA case

Proposed Solution

No response