[jedberg]

Posted elsewhere, but yeah that's my theory too (having actually helped built it in the first place). My guess is the caches got blown out because the entire system is built on the idea that most people are looking at the most popular content.

When you close down all the most popular content, you have to dig deep into the long tail for fresh content.

Also, my guess is that the code for building homepages is not optimized for having a lot of skips due to private Reddits, since most people have probably never been subscribed to a private reddit, or if they have it wasn't for very long, or even if for very long, never more than one or two at at time.

[biesnecker]

Makes sense to me. I remember several lunch conversations at FB about whether or not we even could restart the site with totally cold caches. I’m sure it was possible but it wouldn’t have been clean or pretty.

[jedberg]

We did restart reddit with cold caches a few times when I was there. It took hours to recover but eventually caught up if it happened near peak. If we did it during low traffic it wasn't too bad.

But that was 13 years ago, no idea how it would do today. :)

[biesnecker]

I’m sure Facebook could too (their disaster recovery planning and drills were always top notch) but I’m glad I won’t be oncall if it ever happens :-D

[_dain_]

> I remember several lunch conversations at FB about whether or not we even could restart the site with totally cold caches

so you're saying, we just have to knock it out once, and it'll be gone forever? that makes things easier ...