Linux 为什么两个不同的系统在apache2中每个进程使用的内存有这么大的差异？

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

在服务器1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

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

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 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

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

为什么使用了如此多的内存差异

在阅读了一些文档和谷歌搜索之后，我想到了加载的模块，但每台服务器之间并没有太大的区别

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，结果相同

---

我还可以检查什么来理解这种差异？

问题在于模块安全性2

启用模块后（每个进程120-160MB）

禁用模块时（每个进程9-15MB）

---

您可以在此处进行电子邮件对话：

可能是事件MPM的线程？您是否尝试过将Server2配置为像Server1一样使用MPM Prefork？感谢@studersi的回答，是的，正如我已经说过的，我已经在Server2上将MPM模式从Event更改为Prefork，结果相同。您好（我是apache用户的Dino）。您可以关闭自己的答案作为接受。谢谢，完成了！谢谢@dAm2K