A standalone distributed cache stampede coordinator that works with any cache library

[u/OtherwisePush6424]

https://github.com/gkoos/crossflight

Most cache libraries handle the in-process stampede problem fine: concurrent misses for the same key share one Promise. But once you're running multiple servers, each process independently runs the loader. Under load that can be 10, 50, 100 redundant DB calls for the same key.

The usual fix is a Redis lock wrapper, but those couple coordination to a specific cache library and you end up writing the same retry-and-wait loop by hand every time.

Crossflight is meant to solve this: a thin coordination layer you drop onto whatever cache you're already using. It handles lease acquisition, periodic renewal, waiter recovery when the owner dies, pub/sub wake-up, fail-open/fail-closed modes, and per-call timeouts, all through two small interfaces so it works with Redis, cache-manager, Keyv, Cacheable, or anything else.

The Redis coordinator uses Lua scripts for atomic lease acquisition and LISTEN/NOTIFY for efficient waiter wake-up instead of polling.

If you want to see it in action, there's a demo repo that spins up a full stack: 3 Express API instances behind nginx, a slow upstream API (500ms artificial delay), and a shared Redis instance serving as both coordinator and cache backend. You fire 20 concurrent requests and watch all three instances coalesce to a single upstream call.

https://github.com/gkoos/crossflight-demo

Would be curious if anyone's run into this problem and how you're currently handling it.