I am using Apache on RHEL 7 since along
time.
httpd-2.4.6-97.el7_9.x86_64
I use it with mod_mpm_prefork module, the default on Redhat.
I see, shortly after startup, messages in
errorlog like
AH00161: server reached MaxRequestWorkers setting, consider
raising the MaxRequestWorkers setting
I have tried to do that
<IfModule mpm_prefork_module>
StartServers 20
MinSpareServers 10
MaxSpareServers 20
ServerLimit 512
MaxRequestWorkers 512
MaxConnectionsPerChild 10000
</IfModule>
I also tried much higher values of ServerLimit and MaxRequestWorkers, like 6400 or 30'000
It makes no difference, the error message appears.
In server-status, I always see four lines
of 64 servers, i.e. a total of 256 servers shown, like this:
.R_RRRRR_RRRRRKCCC_C..R_RRRKRRCC.R_CCKRKRRRRRKC.KRKR_R.__RKCRRRK .KKRWRC_R_RCRRCKR_KRKKRRKKKKRKRC.C_RRRKR_RRRRC.K................ ................................................................ ................................................................ How can I get beyond these 256 servers? The machine has 64 cores, and 132 Gb RAM.
I know that I can switch to mod_mpm_event, but before I go that way, I would like to know why I cannot more than 256 servers in prefork mode.