我有一对Ubuntu专用服务器。。。
服务器1:
Ubuntu 16.04.7 (64 bits)
16GB RAM
8 Xeon CPU
Apache 2.4.18
MPM mode: prefork
服务器2:
Ubuntu server 20.04.2 (64 bits)
32GB RAM
8 Xeon CPU
2.4.41
MPM mode: event
在Server1上，每个apache2进程使用7MB到18MB的RAM。。。
ps axo 'user rss cmd' | grep apache | grep -v "(root|grep|tomcat)"
www-data 18232 /usr/sbin/apache2 -k start
www-data 11700 /usr/sbin/apache2 -k start
www-data 11276 /usr/sbin/apache2 -k start
www-data 10792 /usr/sbin/apache2 -k start
www-data 11216 /usr/sbin/apache2 -k start
www-data 11600 /usr/sbin/apache2 -k start
www-data 10336 /usr/sbin/apache2 -k start
www-data 11356 /usr/sbin/apache2 -k start
www-data 11348 /usr/sbin/apache2 -k start
www-data 10980 /usr/sbin/apache2 -k start
www-data 11316 /usr/sbin/apache2 -k start
www-data 6808 /usr/sbin/apache2 -k start
在Server2上，每个apache2进程使用120MB到130MB的RAM。。。
ps axo 'user rss cmd' | grep apache | grep -v "(root|grep|tomcat)"
www-data 120436 /usr/sbin/apache2 -k start
www-data 119784 /usr/sbin/apache2 -k start
www-data 128720 /usr/sbin/apache2 -k start
www-data 130208 /usr/sbin/apache2 -k start
为什么使用了如此大的记忆力差异？
在阅读了一些文档和谷歌后，我考虑了加载的模块，但每个服务器之间没有太大区别。。。
服务器1
# apache2 -M
Loaded Modules:
core_module (static)
so_module (static)
watchdog_module (static)
http_module (static)
log_config_module (static)
logio_module (static)
version_module (static)
unixd_module (static)
access_compat_module (shared)
actions_module (shared)
alias_module (shared)
auth_basic_module (shared)
auth_digest_module (shared)
auth_openidc_module (shared)
authn_core_module (shared)
authn_file_module (shared)
authz_core_module (shared)
authz_host_module (shared)
authz_user_module (shared)
autoindex_module (shared)
bw_module (shared)
cgi_module (shared)
dav_module (shared)
dav_fs_module (shared)
dav_lock_module (shared)
deflate_module (shared)
dir_module (shared)
env_module (shared)
expires_module (shared)
fcgid_module (shared)
filter_module (shared)
headers_module (shared)
include_module (shared)
mime_module (shared)
mpm_prefork_module (shared)
negotiation_module (shared)
proxy_module (shared)
proxy_balancer_module (shared)
proxy_fcgi_module (shared)
proxy_http_module (shared)
rewrite_module (shared)
setenvif_module (shared)
slotmem_shm_module (shared)
socache_shmcb_module (shared)
ssl_module (shared)
status_module (shared)
suexec_module (shared)
userdir_module (shared)
服务器2
# apache2 -M
Loaded Modules:
core_module (static)
so_module (static)
watchdog_module (static)
http_module (static)
log_config_module (static)
logio_module (static)
version_module (static)
unixd_module (static)
access_compat_module (shared)
aclr_module (shared)
actions_module (shared)
alias_module (shared)
auth_basic_module (shared)
auth_digest_module (shared)
auth_openidc_module (shared)
authn_core_module (shared)
authn_file_module (shared)
authz_core_module (shared)
authz_host_module (shared)
authz_user_module (shared)
autoindex_module (shared)
cgid_module (shared)
dav_module (shared)
dav_fs_module (shared)
dav_lock_module (shared)
deflate_module (shared)
dir_module (shared)
env_module (shared)
fcgid_module (shared)
filter_module (shared)
headers_module (shared)
include_module (shared)
mime_module (shared)
mpm_event_module (shared)
negotiation_module (shared)
proxy_module (shared)
proxy_balancer_module (shared)
proxy_fcgi_module (shared)
proxy_http_module (shared)
remoteip_module (shared)
reqtimeout_module (shared)
rewrite_module (shared)
security2_module (shared)
setenvif_module (shared)
slotmem_shm_module (shared)
socache_shmcb_module (shared)
ssl_module (shared)
status_module (shared)
suexec_module (shared)
unique_id_module (shared)
userdir_module (shared)
我已经在Server2上将MPM模式从Event更改为Prefork，得到了相同的结果。
我还可以检查什么来理解这种差异？
问题出在模块安全性2上。
启用模块(每个进程120-160MB(。。。
# ps axo 'user rss cmd' | grep apache | grep -v "(root|grep|tomcat)"
www-data 121232 /usr/sbin/apache2 -k start
www-data 120596 /usr/sbin/apache2 -k start
www-data 156816 /usr/sbin/apache2 -k start
www-data 162668 /usr/sbin/apache2 -k start
模块被禁用(每个进程9-15MB(。。。
# a2dismod security2
Module security2 disabled.
To activate the new configuration, you need to run:
systemctl restart apache2
# systemctl restart apache2
# ps axo 'user rss cmd' | grep apache | grep -v "(root|grep|tomcat)"
www-data 10340 /usr/sbin/apache2 -k start
www-data 9764 /usr/sbin/apache2 -k start
www-data 14164 /usr/sbin/apache2 -k start
www-data 14220 /usr/sbin/apache2 -k start
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