Recent Incidents with Increased 499 Errors

This past Sunday we had a large increase of 499 errors to one of our sites. We also had the same situation last night for about 15-20 minutes. Some users (mostly mobile) reported the issue with some errors on pages.

Both incidents were proceeded by a specific IP from AWS reaching out to a bunch of scripts/pages and not getting any 200 OKs. When looking at the event logs Cloudflare eventually blocks the IP.

The incident on Sunday seemed to last from 2PM CST to ~midnight CST. Last night only 15-20 minutes.

Site24x7 reported downtime during the entire incident on Sunday and last night. Cloudflare reported no downtime and a majority of the requests seemed to process as normal.

I blocked the IP at a Cloudflare level because it only occurred those 2 times in 7 days.

Would you be able to provide more information specifically on the 499 error and is this something on the Cloudflare side or something that can be handled at the origin at all?

Wonder if it might be something similar as happened here, or rather something else in the meantime :thinking:

The only reason I don’t think this is the case is because it happened at very specific times and just recently. This does not seem to be an ongoing/iOS issue.