Nice comment, you opened a new perspective on this. >But what if you actually do want your dependency list to trigger invalidation? I (we, as it was a team) o

Nice comment, you opened a new perspective on this. >But what if you actually do want your dependency list to trigger invalidation? I (we, as it was a team) once had a scenario where there was a big dependency graph with a lot of replicas (not necessarily caches but a similar thing) and if we just used TTLs the effect on the whole thing was that there were some periods of time where we've just got a flood of nodes (children, grandchildren, and so on) all wanting to update at the same time, talking to each other and whatnot. In the end the solution was quite complex as it was a combination of a short TTL, some random delays here and there to lower the probability of things happening at the exact same time, very low message overhead and a system akin to ETags in HTTP [1]. It was very hard due to the scale of the whole system and I'm sure Meta has this problem 100x so, disregarding the poor choice of title, it was an interesting read nonetheless. 1: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ET...