접속장애가 있었습니다.

약 30분정도 접속 장애가 있었습니다.
웹서버인 nginx가 재시작을 못하면서 접속이 안되었습니다.
log 에는
nginx.service - nginx - high performance web server Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled) Active: failed (Result: exit-code) since Tue 2018-07-31 15:10:14 KST; 42s ago Docs: http://nginx.org/en/docs/ Process: 2473 ExecStop=/bin/kill -s TERM $MAINPID (code=exited, status=0/SUCCESS) Process: 2442 ExecReload=/bin/kill -s HUP $MAINPID (code=exited, status=0/SUCCESS) Process: 2922 ExecStart=/usr/sbin/nginx -c /etc/nginx/nginx.conf (code=exited, status=1/FAILURE) Main PID: 1315 (code=exited, status=0/SUCCESS) Jul 31 15:10:14 ubuntu systemd[1]: Stopped nginx - high performance web server. Jul 31 15:10:14 ubuntu systemd[1]: Starting nginx - high performance web server... Jul 31 15:10:14 ubuntu nginx[2922]: nginx: [emerg] unknown directive "more_set_headers" in /etc/nginx/nginx.conf:35 Jul 31 15:10:14 ubuntu systemd[1]: nginx.service: Control process exited, code=exited status=1 Jul 31 15:10:14 ubuntu systemd[1]: Failed to start nginx - high performance web server. Jul 31 15:10:14 ubuntu systemd[1]: nginx.service: Unit entered failed state. Jul 31 15:10:14 ubuntu systemd[1]: nginx.service: Failed with result 'exit-code'.
라고 되어있어서
램을 2기가 증설했는데도 재기동이 안되서
살펴보니
최근 수정한 설정파일에 문제가 있었습니다.