In the error.log log, nginx found entries:
2016/10/19 09:19:36 [error] 30110 # 0: * 222886 open () "/home/public/images/xxx.jpg" failed (2: No such file or directory), client: 123.123.123.123 , server: site.ru, request: "GET /images/xxx.jpg HTTP / 1.1", host: "site.ru", referrer: " http://site.ru/ "
Someone bot requested a file 40 times per second for 12 minutes. The images directory does not exist. The file xxx.jpg exists, but is in the img directory. The presence of the img directory for the site visitor is obvious, the path is written in the address bar of the browser when opening pictures. That is, the incorrect images directory was pointed out to the bot intentionally.
What is the point of launching such a request by a bot? That is, more interested in what the bot wanted to get?