参考：https://www.virtualmin.com/node/37310

i found from where heartbeat module was called: /etc/httpd/conf.modules.d/00-proxy.conf

因此，删除或者注释。

报错：Job for httpd.service failed because the control process exited with error code

参考：https://www.cnblogs.com/itslives-com/p/Job_for_httpd_service_failed.html

输入：

systemctl status httpd.service

输出：

httpd: Syntax error on line 60 of /etc/httpd/conf/httpd.conf: Syntax error on line 1 of /etc/httpd/conf.modules.d/10-proxy_h2.conf: Cannot load modules/mod_proxy_http2.so into server: /etc/httpd/modu>

报错：Cannot define multiple Listeners on the same IP:port

参考：https://serverfault.com/questions/932727/apache-2-4-updated-now-throws-cannot-define-multiple-listeners-on-the-same-ip