My website, which typically has very low volume, suddenly received a huge spike in traffic all from the same user agent. We were receiving about 3 requests per second for a sustained period of about an hour all from the user agent "Facebot Twitterbot." The requests all look like this, to one URI:
Dec 16 00:35:36 website app/web.1 10.1.52.64 - - [16/Dec/2021:02:35:36 -0600] "GET /signup/ HTTP/1.1" 200 2299 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_1) AppleWebKit/601.2.4 (KHTML, like Gecko) Version/9.0.1 Safari/601.2.4 facebookexternalhit/1.1 Facebot Twitterbot/1.0"
We had a similar traffic event to another page in the past that lasted a bit longer about two weeks ago. This isn't a huge problem, since the site can handle the traffic and it seems to end after some time, but it does slow the response time by a few milliseconds typically and it spams our logs and makes it difficult to debug actual problems that crop up.
I have looked into this user agent a bit (see: here and here) it seems to be an IOS imessage utility function, though it it still unclear what exactly causes it. Is this traffic normal, should I have any reason to be concerned?