On the clean install Ubuntu 14.04 with Apache without almost any client load the Apache server with the command "service apache2 reload" itself allocates slots marked with "Gracefully finishing" for which rejects new connections.
For full rejection of new requests is sufficient to perform 4x command "service apache2 reload".
5/ service apache2 reload -> Server Apache not responding
With logs in apache error log file:
... [mpm_event:error] [pid 9381:tid 1234563234] AH00485: scoreboard is full, not at MaxRequestWorkers
...
#################################################
My workaround was change to MPM module from "mpm_event" to "mpm_worker".
On the clean install Ubuntu 14.04 with Apache without almost any client load the Apache server with the command "service apache2 reload" itself allocates slots marked with "Gracefully finishing" for which rejects new connections.
For full rejection of new requests is sufficient to perform 4x command "service apache2 reload".
Ubuntu 14.04.2 LTS
Apache 2.4.7-ubuntu4.4 (mpm_event)
Kernel 2.16.0-30-generic
Reproduce problem: ####### ####### ####### ####### ####### ####### _______ _______ _______ _______ _______ _______ _____W_ _______ _ ____... ....... ....... ....... ....... ....... ....... ....... . ....... ....... .
#######
1/ service apache2 start
_______
_______
.......
2/ service apache2 reload
....... ....... ....... ....GGGGGGGGGGG GGGGGGGGGGGGGGG GGGGGGGGGGGGG _______ _______ _______ _______ _______ _______ _______ W__ _______ _______ _
GGGGGGGGGGG_
_______
3/ service apache2 reload
___W___ _______ _______ ____GGGGGGGGGGG GGGGGGGGGGGGGGG GGGGGGGGGGGGG _______ _______ _______ _______ _______ _______ _______ ... ....... ....... .
GGGGGGGGGGG_
.......
4/ service apache2 reload
GGGGGGGGGGGGGGG GGGGGGGGGGGGGGG GGGGGGGGGGGGGGG GGGGGGGGGGGGGGG GGGG GGGGGGGGGGGGGGG GGGGGGGGGGGGGGG GGGGGGGGGGGGGGG G___ _______ _______ _
GGGGGGGGGGGGGGG
W______
5/ service apache2 reload -> Server Apache not responding ####### ####### ####### ####### ####### #######
With logs in apache error log file:
... [mpm_event:error] [pid 9381:tid 1234563234] AH00485: scoreboard is full, not at MaxRequestWorkers
...
#######
My workaround was change to MPM module from "mpm_event" to "mpm_worker".