Yes, it is. The worst offenders hammer us (and others) with thousands upon thousands of requests, and each request uses unique IP addresses making all per-IP limits useless.

We implemented an anti-bot challenge and it helped for a while. Then our server collapsed again recently. The perf command showed that the actual TLS handshakes inside nginx were using over 50% of our server's CPU, starving other stuff on the machine.

It's a DDoS.

You should see Cloudflare's control panel for AI bot blocking. There are dozens of different AI bots you can choose to block, and that doesn't even count the different ASNs they might use. So in this case I'd say that a DDoS is a decent description. It's not as bad as every home router on the eastern seaboard or something, but it's pretty bad.

Uncoordinated DDoS, when multiple search and AI companies are hammering your server.

> Are you sure it's a DDoS and not just a DoS?

I think these days it’s ‘DAIS’, as in your site just DAIS - from Distributed/Damned AI Scraping

When every AI company does it from multiple data centers... yes it's distributed.