ubuntu-8.04-apache-easy-install-and-configuration-and-source-build

apt-get purge x-11

ed                                              install
emacs21-bin-common                              install
emacs21-common                                  install
emacs21-el                                      install
emacs21-nox                                     install
emacsen-common 

gnome-bin                                       install
gnome-libs-data                                 install
joe
mailx                                           install

psa-courier-imap                                install
psa-courier-imap-add                            install


psa-qmail                                       install

sendmail-base                                   deinstall
sendmail-bin                                    deinstall
sendmail-cf                                     install
sendmail-doc                                    install






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THE EASY WAY WITH APT-GET

apt-get install apache2.2-common	

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SHOWS YOU WHAT'S ALREADY INSTALLED

dpkg --get-selections > installed-software.txt
apt-get autoremove

dpkg --set-selections < installed-software.txt
dselect						//allow to unselect packages?

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If required you can remove & install apache2-common again

apt-get purge apache2-common
cd /etc/apache2 
rm -R * 		//be careful that you really are in /etc/apache2!!!!
cd ..
rmdir apache2

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The configuration file is at (Ubuntu) /etc/apache2/apache2.conf
Log files at /var/log/apache2/access.log 	(error.log)


Whenever you modify a configuration file you will have to run the following commands (ubuntu specific)

/etc/init.d/apache2 stop
/etc/init.d/apache2 start

To see the changes… or a slightly “nicer” command is to use the Apache control command:

/usr/sbin/apache2ctl directive   e.g. sudo apache2ctl graceful

Directives: start / stop / graceful (restarts w/ aborting connections) / restart / status / 

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SECURITY: SEE apache-setup-security.txt for tips on how to make it more secure...
e.g. ServerTokens Full to Server Tokens Prod
ServerSignature Off 
UseCanonicalName Off
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ports.conf contains the listen ports config, e.g. Listen 80  <IfModule mod_ssl.c> Listen 443 </IfModule>
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SLIGHT OPTIMIZATIONS: /etc/apache2/apache2.conf



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STATISTICS AND PERFORMANCE

apt-get install apache2.2-common
apt-get install apache2

df -h goes from 450MB to 461MB

DEFAULT:
free returns 118MB used 

ps -aux
USER    PID     CPU  MEM    VSZ     RSS TTY         START           COMMAND
root      4417  0.0  0.6  10472  2584 ?        Ss   15:30   0:00 /usr/sbin/apache2 -k start
www-data  4418  0.0  0.4  10244  1780 ?        S    15:30   0:00 /usr/sbin/apache2 -k start
www-data  4420  0.0  0.6 231808  2396 ?        Sl   15:30   0:00 /usr/sbin/apache2 -k start
www-data  4424  0.0  0.6 231808  2400 ?        Sl   15:30   0:00 /usr/sbin/apache2 -k start

VSZ is a decimal integer, the size in kilobytes of the process in virtual memory.

VSZ includes RSS... Virtual memory usage of entire process = VmLib + VmExe + VmData + VmStk

RSS is real memory (resident set) size of the process in pages in 1KB units

Thus VSZ for apache2 = 231,808 KB x 2 = 500KB...

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Dynamically loaded modules: code is loaded when the module is required

Static mode comes at a price — the more modules, the more memory you use. Thus, a forked
multi-processing module can have a significant effect on the machine's memory requirements.



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MPM WORKER versus PREFORK

Multi-Processing Module with PHP... http://brian.moonspot.net/2008/02/13/apache-worker-and-php/

mpm_prefork_module

 each apache/php process allocates it's own memory, at ~15MB per process x 50 = 750MB RAM

 Having a prefork Apache/PHP process that has 15MB of RAM allocated serve a 10k jpeg image or some CSS file is a waste of resources. 

mpm_worker_module

    each worker process can have 5 child processes with 10 threads BUT they can reuse memory from 
    other threads in the same process

YOU cannot use radical php extensions ...