Servers lie down from empty HEAD requests how to overcome?

Question

System administration

Dear hello!
Servers crash from empty HEAD requests, user agents are different, there is no referrer.
These are not bots, I understand when search bots come in .. but here it’s just different browsers ..
Here is a piece from the log

116.231.90.3 - - [25/Feb/2019:12:43:10 +0200] "HEAD /watch/ami-ki-tomake-khub-birokto-korchi-cover-song-bengali-new-song/_NVvYMXhtzg HTTP/1.0" 200 - "-" "Mozilla/5.0 (compatible; MSIE 10.0; Macintosh; Intel Mac OS X 10_7_3; Trident/6.0)"
62.99.178.46 - - [25/Feb/2019:12:43:11 +0200] "HEAD /watch/obrabotka-poni-zakat-podarok-dlya-emon-pie-ili-sanshi-chan-chitayte-opisanie/EWrJAjVmLAk HTTP/1.0" 200 - "-" "Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120403211507 Firefox/14.0.1"
82.135.249.196 - - [25/Feb/2019:12:43:11 +0200] "HEAD /watch/sleep-well/ZbVeFEHOaJQ HTTP/1.0" 200 - "-" "Mozilla/5.0 (Windows; U; Windows NT 6.1; zh-TW; rv:1.9.2.4) Gecko/20100611 Firefox/3.6.4 ( .NET CLR 3.5.30729)"
169.255.127.137 - - [25/Feb/2019:12:43:11 +0200] "HEAD /watch/ppap-game-high-score-pineapple-pen-apple-pen-game/Do-aGlfTNIE HTTP/1.0" 200 - "-" "Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 6.1; chromeframe/12.0.742.100; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C)"
116.231.90.3 - - [25/Feb/2019:12:43:11 +0200] "HEAD /watch/mick-martin-the-blues-rockers-i-believe-in-you/V_kwDPUjBkU HTTP/1.0" 200 - "-" "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:21.0) Gecko/20100101 Firefox/21.0"
177.52.249.128 - - [25/Feb/2019:12:43:11 +0200] "HEAD /watch/kak-legko-sdat-oge-po-literature-na-maksimum-moy-opit/zsUklqcR-yk HTTP/1.0" 200 - "-" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/534.14 (KHTML, like Gecko) Chrome/10.0.602.0 Safari/534.14"
82.135.249.196 - - [25/Feb/2019:12:43:12 +0200] "HEAD /watch/shtamboviy-krizhovnik-pakspravila-ukhoda-i-plodonoshenie/iuXdbqvcLxw HTTP/1.0" 200 - "-" "Opera/9.80 (X11; Linux i686; U; en-GB) Presto/2.2.15 Version/10.00"
157.55.39.82 - - [25/Feb/2019:12:43:13 +0200] "GET /user/UCoLrcjPV5PbUrUyXq5mjc_A HTTP/1.0" 302 20 "-" "Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)"
169.255.127.137 - - [25/Feb/2019:12:43:12 +0200] "HEAD /watch/uzi-sosudov-golovnogo-mozga/bs_0Vd95K2k HTTP/1.0" 200 - "-" "Mozilla/5.0 (X11; U; Linux i686; de; rv:1.9.2.15) Gecko/20110330 CentOS/3.6-1.el5.centos Firefox/3.6.15"
177.52.249.128 - - [25/Feb/2019:12:43:13 +0200] "HEAD /watch/worst-kool-aid-ever-ragnas-day-1/QzT5cLyDWMM HTTP/1.0" 200 - "-" "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_6; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.134 Safari/534.16"
116.231.90.3 - - [25/Feb/2019:12:43:13 +0200] "HEAD /watch/the-saints-stranded/Q-GueNOKolo HTTP/1.0" 200 - "-" "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.14 (KHTML, like Gecko) Chrome/24.0.1292.0 Safari/537.14"
82.135.249.196 - - [25/Feb/2019:12:43:13 +0200] "HEAD /watch/strizhka-graduirovannoe-bob-kare-strizhka-kare-na-nozhke/x6pfsJ7Hc3E HTTP/1.0" 200 - "-" "Mozilla/5.0 (X11; U; CrOS i686 0.9.128; en-US) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.552.341 Safari/534.10"
169.255.127.137 - - [25/Feb/2019:12:43:14 +0200] "HEAD /watch/ak-scumfam-round-here-music-video-freekdot/lDERDYxjHLI HTTP/1.0" 200 - "-" "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.3 (KHTML, like Gecko) Chrome/6.0.460.0 Safari/534.3"

It all started a week ago ..
Requests exclusively go from morning to evening, at night the servers take a break from this ..
At first there were requests from 1 ip to all 4 servers, everything calmed down and after half a day it started again but with 4 different ip also banned them and again after a while on a new one.
Maybe generally prohibit HEAD requests, but allow them only to search engines?
I don’t understand how to do it ..
HELP help ..

Answer 1

Use fail2ban to analyze logs and block unwanted IPs automatically.