Are there specific Apache modules that take up memory? I've read the Apache performance tuning manuals, some Apache forums and googled around for "apache httpd process/thread memory module" etc. but couldn't find anything conclusive.
On our server we have the following modules: core mod_access mod_auth mod_include mod_log_config mod_env mod_headers
mod_setenvif mod_ssl prefork http_core mod_mime mod_dav mod_status
mod_autoindex mod_asis mod_cgi mod_dav_fs mod_negotiation mod_dir
mod_imap mod_actions mod_userdir mod_alias mod_so sapi_apache2
Looks slightly excessive, I went through the list but I'm not sure which ones are 100% futile. Dav is for the "webfolders" possibility. Autoindex might be one to go. Are there places where Moodle might benefit from mod_asis (send-as-is)?
On another server (Ubuntu) httpd processes take 15-20 Mb for Moodle, I have mostly the same modules except SSL and DAV. The PHP modules don't seem to matter that much, the test server has "everything" loaded on the PHP side, the "culprit" (SuSe Enterprise 9) server has less PHP modules, but it eats 35-40 Mb per process (physical memory, RES in "top").
How to reduce the amount of memory that each httpd process takes?
by Samuli Karevaara -
Number of replies: 1
In reply to Samuli Karevaara
Re: How to reduce the amount of memory that each httpd process takes?
by Samuli Karevaara -
I never had the time nor the expertise to find out what this was, but just reporting: we upgraded to Apache 2.2.3, PHP 5.2.0 and MySQL 5.0.27 (From 2.0, 4.1 and 4.1 respectively) and on the same server the top reports that httpd processes take <10M (RES) each, and almost half of that reported as shared (SHR) 
Must be a memory-model change somewhere deep in the system, but things seem to be running smoothly now so happy happy joy joy for us
Must be a memory-model change somewhere deep in the system, but things seem to be running smoothly now so happy happy joy joy for us