报错：
Oct 31 09:28:14 centos7 httpd[31657]: (98)Address already in use: AH00072: make_sock: could not bind to address [::]:80
Oct 31 09:28:14 centos7 httpd[31657]: (98)Address already in use: AH00072: make_sock: could not bind to address 0.0.0.0:80
Oct 31 09:28:14 centos7 httpd[31657]: no listening sockets available, shutting down
Oct 31 09:28:14 centos7 httpd[31657]: AH00015: Unable to open logs
Oct 31 09:28:14 centos7 systemd[1]: httpd.service: main process exited, code=exited, status=1/FAILURE
Oct 31 09:28:14 centos7 kill[31659]: kill: cannot find process ""
Oct 31 09:28:15 centos7 systemd[1]: httpd.service: control process exited, code=exited status=1
Oct 31 09:28:15 centos7 systemd[1]: Failed to start The Apache HTTP Server.
Oct 31 09:28:15 centos7 systemd[1]: Unit httpd.service entered failed state.
Oct 31 09:28:15 centos7 systemd[1]: httpd.service failed.
解决方法：
killall httpd
或
ps aux|grep httpd
kill -9 ##进程编号##
重启即可
systemctl start httpd