Prefork vs worker module for apache, what is being used?

Question

Having trouble determining which MPM my apache is using, can anyone tell based on following outputs?
My guess is that Prefork is being used?

[root@rp1a ~]# cat /etc/sysconfig/httpd

#HTTPD=/usr/sbin/httpd.worker

#OPTIONS=

#HTTPD_LANG=C
ulimit -n 65000
OPTIONS="-D SetCacheHeaders -D Gzip -D front"

[root@rp1a ~]# tail /etc/httpd/conf.d/rp-base.conf

<IfModule prefork.c>
StartServers       8
MinSpareServers    5
MaxSpareServers   20
ServerLimit      256
MaxClients       256
MaxRequestsPerChild  4000
</IfModule>

[root@rp1a ~]# apachectl -V

Server version: Apache/2.2.3
Server built:   Jun 13 2013 10:45:37
Server's Module Magic Number: 20051115:3
Server loaded:  APR 1.2.7, APR-Util 1.2.7
Compiled using: APR 1.2.7, APR-Util 1.2.7
Architecture:   64-bit
Server MPM:     Prefork
threaded:     no
    forked:     yes (variable process count)
Server compiled with....
-D APACHE_MPM_DIR="server/mpm/prefork"
-D APR_HAS_SENDFILE
-D APR_HAS_MMAP
-D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
-D APR_USE_SYSVSEM_SERIALIZE
-D APR_USE_PTHREAD_SERIALIZE
-D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
-D APR_HAS_OTHER_CHILD
-D AP_HAVE_RELIABLE_PIPED_LOGS
-D DYNAMIC_MODULE_LIMIT=128
-D HTTPD_ROOT="/etc/httpd"
-D SUEXEC_BIN="/usr/sbin/suexec"
-D DEFAULT_PIDLOG="run/httpd.pid"
-D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
-D DEFAULT_LOCKFILE="logs/accept.lock"
-D DEFAULT_ERRORLOG="logs/error_log"
-D AP_TYPES_CONFIG_FILE="conf/mime.types"
-D SERVER_CONFIG_FILE="conf/httpd.conf"

[root@rp1a ~]# /usr/sbin/httpd -V

Server version: Apache/2.2.3
Server built:   Jun 13 2013 10:45:37
Server's Module Magic Number: 20051115:3
Server loaded:  APR 1.2.7, APR-Util 1.2.7
Compiled using: APR 1.2.7, APR-Util 1.2.7
Architecture:   64-bit
Server MPM:     Prefork
  threaded:     no
    forked:     yes (variable process count)
Server compiled with....
 -D APACHE_MPM_DIR="server/mpm/prefork"
 -D APR_HAS_SENDFILE
 -D APR_HAS_MMAP
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
 -D APR_USE_SYSVSEM_SERIALIZE
 -D APR_USE_PTHREAD_SERIALIZE
 -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
 -D APR_HAS_OTHER_CHILD
 -D AP_HAVE_RELIABLE_PIPED_LOGS
 -D DYNAMIC_MODULE_LIMIT=128
 -D HTTPD_ROOT="/etc/httpd"
 -D SUEXEC_BIN="/usr/sbin/suexec"
 -D DEFAULT_PIDLOG="run/httpd.pid"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_LOCKFILE="logs/accept.lock"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="conf/mime.types"
 -D SERVER_CONFIG_FILE="conf/httpd.conf"

[root@rp1a ~]# apachectl -l

Compiled in modules:
  core.c
  prefork.c
  http_core.c
  mod_so.c

[root@rp1a ~]# httpd -l

Compiled in modules:
  core.c
  prefork.c
  http_core.c
  mod_so.c

[root@rp1a ~]# httpd.worker -l

Compiled in modules:
  core.c
  worker.c
  http_core.c
  mod_so.c

[root@rp1a ~]# ps -C httpd.worker -F

UID        PID  PPID  C    SZ   RSS PSR STIME TTY          TIME CMD

[root@rp1a ~]# ps -C httpd -F | head

UID        PID  PPID  C    SZ   RSS PSR STIME TTY          TIME CMD
root      3947     1  0 63439 12092   0 Jul29 ?        00:00:12 /usr/sbin/httpd -D SetCacheHeaders -D Gzip -D front
apache   16411  3947  0 64231  8632   1 13:28 ?        00:00:01 /usr/sbin/httpd -D SetCacheHeaders -D Gzip -D front
apache   16501  3947  0 64231  9372   1 13:32 ?        00:00:01 /usr/sbin/httpd -D SetCacheHeaders -D Gzip -D front
apache   16662  3947  0 64149  8452   1 13:40 ?        00:00:01 /usr/sbin/httpd -D SetCacheHeaders -D Gzip -D front
apache   16807  3947  0 64199  8688   1 13:50 ?        00:00:01 /usr/sbin/httpd -D SetCacheHeaders -D Gzip -D front
apache   16814  3947  0 64147  8452   1 13:51 ?        00:00:01 /usr/sbin/httpd -D SetCacheHeaders -D Gzip -D front
apache   16836  3947  0 64199  8612   1 13:51 ?        00:00:01 /usr/sbin/httpd -D SetCacheHeaders -D Gzip -D front
apache   16876  3947  0 64231  9204   1 13:51 ?        00:00:01 /usr/sbin/httpd -D SetCacheHeaders -D Gzip -D front
apache   16935  3947  0 64139  8452   1 13:54 ?        00:00:01 /usr/sbin/httpd -D SetCacheHeaders -D Gzip -D front

Answer 1

Server MPM: Prefork

So, yes, prefork seems to be used used. But to be sure that you are looking at the correct binary, try /usr/sbin/httpd -V .