I am having an issue with NGINX 1.7.11 opening UDP connections to local resolver via loopback to pdns-recursor and exhausting sockets. After restarting NGINX the socket count keeps growing and within a couple of hours socket resource get exhausted causing NGINX lookup issues.

nginx 4080 nobody 853u IPv4 345685655 0t0 UDP 127.0.0.1:40023->127.0.0.1:domain
nginx 4080 nobody 854u IPv4 345740591 0t0 UDP 127.0.0.1:41812->127.0.0.1:domain
nginx 4080 nobody 855u IPv4 345907719 0t0 UDP 127.0.0.1:34571->127.0.0.1:domain
nginx 4080 nobody 859u IPv4 345539650 0t0 UDP 127.0.0.1:16773->127.0.0.1:domain
nginx 4080 nobody 869u IPv4 345832059 0t0 UDP 127.0.0.1:62564->127.0.0.1:domain
nginx 4080 nobody 874u IPv4 346024303 0t0 UDP 127.0.0.1:18875->127.0.0.1:domain
nginx 4080 nobody 880u IPv4 345574459 0t0 UDP 127.0.0.1:12311->127.0.0.1:domain
nginx 4080 nobody 882u IPv4 345663551 0t0 UDP 127.0.0.1:57025->127.0.0.1:domain
nginx 4080 nobody 884u IPv4 345714822 0t0 UDP 127.0.0.1:28468->127.0.0.1:domain
nginx 4080 nobody 900u IPv4 345591722 0t0 UDP 127.0.0.1:61516->127.0.0.1:domain
nginx 4080 nobody 917u IPv4 345763169 0t0 UDP 127.0.0.1:33232->127.0.0.1:domain
nginx 4080 nobody 920u IPv4 345653981 0t0 UDP 127.0.0.1:45393->127.0.0.1:domain
nginx 4080 nobody 931u IPv4 345897689 0t0 UDP 127.0.0.1:42684->127.0.0.1:domain
nginx 4080 nobody 942u IPv4 345549356 0t0 UDP 127.0.0.1:53081->127.0.0.1:domain
nginx 4080 nobody 957u IPv4 345856900 0t0 UDP 127.0.0.1:58400->127.0.0.1:domain
nginx 4080 nobody 959u IPv4 345758072 0t0 UDP 127.0.0.1:59482->127.0.0.1:domain
nginx 4080 nobody 968u IPv4 345422687 0t0 UDP 127.0.0.1:10754->127.0.0.1:domain
nginx 4080 nobody 972u IPv4 345536342 0t0 UDP 127.0.0.1:61019->127.0.0.1:domain
nginx 4080 nobody 991u IPv4 345532191 0t0 UDP 127.0.0.1:13538->127.0.0.1:domain
nginx 4080 nobody 994u IPv4 345428373 0t0 UDP 127.0.0.1:12913->127.0.0.1:domain
nginx 4080 nobody 997u IPv4 345558150 0t0 UDP 127.0.0.1:34043->127.0.0.1:domain
nginx 4080 nobody 1010u IPv4 345826971 0t0 UDP 127.0.0.1:21995->127.0.0.1:domain
nginx 4080 nobody 1011u IPv4 345575388 0t0 UDP 127.0.0.1:62414->127.0.0.1:domain
nginx 4080 nobody 1013u IPv4 345918724 0t0 UDP 127.0.0.1:41506->127.0.0.1:domain
nginx 4080 nobody 1032u IPv4 345646127 0t0 UDP 127.0.0.1:14404->127.0.0.1:domain
nginx 4080 nobody 1053u IPv4 345538461 0t0 UDP 127.0.0.1:11756->127.0.0.1:domain
nginx 4080 nobody 1061u IPv4 345548737 0t0 UDP 127.0.0.1:47851->127.0.0.1:domain
nginx 4080 nobody 1070u IPv4 345742734 0t0 UDP 127.0.0.1:46779->127.0.0.1:domain
nginx 4080 nobody 1089u IPv4 345539560 0t0 UDP 127.0.0.1:20583->127.0.0.1:domain
nginx 4080 nobody 1091u IPv4 345630869 0t0 UDP 127.0.0.1:43817->127.0.0.1:domain