Comment by wiredfool

What’s more, they will scale up with increased resources on the site.

If you redline at 20 searches a sec, and put in 4 more workers, suddenly you’re serving 100r/sec to the bots, paying 5x for it, and your users are still seeing shit qos. I've seen multiple cores of nginx saturated just dealing with one dos/crawl run on a somewhat high profile site.