Apache goes down every few days

Hello all, I’m trying to find a solution why apache stops constantly about every week. Sometimes mysql also and the need a restart to work again. I use Ubuntu Linux 16.04.3, Webmin version 1.872 and Virtualmin version 6.02. My droplet has 2 VCPU, 4GB RAM, 80 Hard Drive. My installation is clean, I have not added or changed anything. The most extreme thing I did is to increase space on digital ocean. What

I can see on apache error log is:

Mon Mar 12 04:51:26.202652 2018] [fcgid:warn] [pid 10923:tid 139857786857344] mod_fcgid: process 13273 graceful kill fail, sending SIGKILL [Mon Mar 12 05:12:51.575849 2018] [fcgid:warn] [pid 10923:tid 139857786857344] mod_fcgid: process 14964 graceful kill fail, sending SIGKILL [Mon Mar 12 05:24:07.158648 2018] [fcgid:warn] [pid 10923:tid 139857786857344] mod_fcgid: process 13271 graceful kill fail, sending SIGKILL [Mon Mar 12 05:41:21.174643 2018] [fcgid:warn] [pid 10923:tid 139857786857344] mod_fcgid: process 16809 graceful kill fail, sending SIGKILL [Mon Mar 12 05:46:43.061688 2018] [fcgid:warn] [pid 10923:tid 139857786857344] mod_fcgid: process 17155 graceful kill fail, sending SIGKILL [Mon Mar 12 05:51:29.944181 2018] [fcgid:warn] [pid 10923:tid 139857786857344] mod_fcgid: process 17521 graceful kill fail, sending SIGKILL [Mon Mar 12 05:57:19.267152 2018] [fcgid:warn] [pid 10923:tid 139857786857344] mod_fcgid: process 18140 graceful kill fail, sending SIGKILL [Mon Mar 12 06:07:35.777688 2018] [fcgid:warn] [pid 10923:tid 139857786857344] mod_fcgid: process 18907 graceful kill fail, sending SIGKILL [Mon Mar 12 06:25:10.350421 2018] [mpm_event:notice] [pid 1831:tid 139857786857344] AH00493: SIGUSR1 received. Doing graceful restart [Mon Mar 12 06:25:10.659935 2018] [core:notice] [pid 1831] AH00060: seg fault or similar nasty error detected in the parent process [Mon Mar 12 07:18:59.580713 2018] [suexec:notice] [pid 24254:tid 140281696900992] AH01232: suEXEC mechanism enabled (wrapper: /usr/lib/apache2/suexec) [Mon Mar 12 07:18:59.598500 2018] [auth_digest:notice] [pid 24255:tid 140281696900992] AH01757: generating secret for digest authentication … [Mon Mar 12 07:18:59.605701 2018] [core:warn] [pid 24255:tid 140281696900992] AH00098: pid file /var/run/apache2/apache2.pid overwritten – Unclean shutdown of previous Apache run? [Mon Mar 12 07:18:59.606791 2018] [mpm_event:notice] [pid 24255:tid 140281696900992] AH00489: Apache/2.4.18 (Ubuntu) mod_fcgid/2.3.9 OpenSSL/1.0.2g configured – resuming normal operations [Mon Mar 12 07:18:59.606809 2018] [core:notice] [pid 24255:tid 140281696900992] AH00094: Command line: ‘/usr/sbin/apache2’ [Mon Mar 12 07:19:26.429963 2018] [core:warn] [pid 24255:tid 140281696900992] AH00045: child process 24261 still did not exit, sending a SIGTERM [Mon Mar 12 07:19:28.431618 2018] [core:warn] [pid 24255:tid 140281696900992] AH00045: child process 24261 still did not exit, sending a SIGTERM [Mon Mar 12 07:19:30.433796 2018] [core:warn] [pid 24255:tid 140281696900992] AH00045: child process 24261 still did not exit, sending a SIGTERM [Mon Mar 12 07:19:32.435943 2018] [core:error] [pid 24255:tid 140281696900992] AH00046: child process 24261 still did not exit, sending a SIGKILL [Mon Mar 12 07:19:33.437141 2018] [mpm_event:notice] [pid 24255:tid 140281696900992] AH00491: caught SIGTERM, shutting down [Mon Mar 12 07:19:34.450660 2018] [fcgid:error] [pid 24258:tid 140281696900992] FastCGI process 24501 still did not exit, terminating forcefully [Mon Mar 12 07:19:36.264629 2018] [suexec:notice] [pid 24695:tid 140038449141632] AH01232: suEXEC mechanism enabled (wrapper: /usr/lib/apache2/suexec) [Mon Mar 12 07:19:36.282998 2018] [auth_digest:notice] [pid 24696:tid 140038449141632] AH01757: generating secret for digest authentication … [Mon Mar 12 07:19:36.291232 2018] [mpm_event:notice] [pid 24696:tid 140038449141632] AH00489: Apache/2.4.18 (Ubuntu) mod_fcgid/2.3.9 OpenSSL/1.0.2g configured – resuming normal operations [Mon Mar 12 07:19:36.291253 2018] [core:notice] [pid 24696:tid 140038449141632] AH00094: Command line: ‘/usr/sbin/apache2’ [Mon Mar 12 07:24:57.965652 2018] [fcgid:warn] [pid 24699:tid 140038449141632] mod_fcgid: process 26560 graceful kill fail, sending SIGKILL [Mon Mar 12 07:27:26.086554 2018] [fcgid:warn] [pid 24699:tid 140038449141632] mod_fcgid: process 25069 graceful kill fail, sending SIGKILL

It is a repeated pattern in my apache error log. I don’t know what all these mean and it would be great to show me some directions! Thank you in advance.