Adding domain causes Bad Gateway error for a few seconds

[Spacedust]

Please see:

[Thu Jul 16 15:57:08 2015] [auth_digest:notice] [pid 28993] [mod_auth_digest.c(236):] [AH01757: generating secret for digest authentication ...] [mail.xxx.pl]
[Thu Jul 16 15:57:09 2015] [mpm_event:notice] [pid 28993] [event.c(2807):] [AH00489: Apache/2.4.16 (Red Hat) OpenSSL/1.0.1e-fips configured -- resuming normal operations] [mail.xxx.pl]
[Thu Jul 16 15:57:09 2015] [core:notice] [pid 28993] [log.c(1536):] [AH00094: Command line: '/usr/sbin/httpd'] [mail.xxx.pl]
[Thu Jul 16 16:00:11 2015] [core:error] [pid 28993] [mpm_unix.c(154):] [AH00046: child process 3341 still did not exit, sending a SIGKILL] [mail.xxx.pl]
[Thu Jul 16 16:00:11 2015] [core:error] [pid 28993] [mpm_unix.c(154):] [AH00046: child process 29341 still did not exit, sending a SIGKILL] [mail.xxx.pl]
[Thu Jul 16 16:00:11 2015] [core:error] [pid 28993] [mpm_unix.c(154):] [AH00046: child process 31401 still did not exit, sending a SIGKILL] [mail.xxx.pl]
[Thu Jul 16 16:00:11 2015] [core:error] [pid 28993] [mpm_unix.c(154):] [AH00046: child process 31403 still did not exit, sending a SIGKILL] [mail.xxx.pl]
[Thu Jul 16 16:00:11 2015] [core:error] [pid 28993] [mpm_unix.c(154):] [AH00046: child process 31540 still did not exit, sending a SIGKILL] [mail.xxx.pl]
[Thu Jul 16 16:00:11 2015] [core:error] [pid 28993] [mpm_unix.c(154):] [AH00046: child process 32258 still did not exit, sending a SIGKILL] [mail.xxx.pl]
[Thu Jul 16 16:00:15 2015] [suexec:notice] [pid 7228] [mod_suexec.c(101):] [AH01232: suEXEC mechanism enabled (wrapper: /usr/sbin/suexec)] [mail.xxx.pl]
[Thu Jul 16 16:00:20 2015] [auth_digest:notice] [pid 7461] [mod_auth_digest.c(236):] [AH01757: generating secret for digest authentication ...] [mail.xxx.pl]
[Thu Jul 16 16:00:21 2015] [mpm_event:notice] [pid 7461] [event.c(2807):] [AH00489: Apache/2.4.16 (Red Hat) OpenSSL/1.0.1e-fips configured -- resuming normal operations] [mail.xxx.pl]
[Thu Jul 16 16:00:21 2015] [core:notice] [pid 7461] [log.c(1536):] [AH00094: Command line: '/usr/sbin/httpd'] [mail.xxx.pl]

[MRatWork]

By default, xxx.yyy domain have 'A record' for mail (aka mail.xxx.yyy).

[Spacedust]

By default, xxx.yyy domain have 'A record' for mail (aka mail.xxx.yyy).

Mail is working fine. I mean why Apache is crashing everytime Kloxo executes apachectl graceful ? It does not happen when I do it manually...

[MRatWork]

Using 'apachectl graceful' or 'service httpd graceful'?.

[Spacedust]

Using 'apachectl graceful' or 'service httpd graceful'?.

Using /etc/init.d/httpd graceful