I've read here multiple reports of people suffering disruption in their forge instances because broken web crawlers.

I have not noticed anything, but: 1. I don't use a forge but cgit (and I cache aggressively), 2. I am blocking a long list of bad user agents at nginx level, 3. I don't have monitoring

So it may be all down to the last point, isn't it?

(although I have never seen any load over 0.16 or so, doesn't mean it is not happening)

Had 216k requests on my cgit host just yesterday. So... yes, I'm experiencing the same issue, is just that I'm not really paying attention

First offending IP in the lot... owned by Alibaba Cloud. Of course.

Not an identifiable user agent. Bastards!