The Apache2 web server has two mods which can be used to compress data sent to the client (ie browser); mod_deflate and mod_gzip. The gzip mod is more versatile but more challenging to setup. For simple compression of HTML, CSS and JavaScript files, the deflate mod works just file. Compression is particularly important on Amazon Web Services (AWS) because:
- HTML is very redundant and bulky
- Smaller files are sent to the client faster
- AWS charges you based upon OUTPUT bandwidth; smaller files = less bandwidth usage per file
Simple activation of mod_deflate
These instructions assume you have already setup an AWS instance and have an SSH client (like PuTTY) available and a SCP client (like WinSCP) to use when editing the configuration files.
- Log in to your instance via the SCP client then open the apache2 virtual hosts configuration file ("/etc/httpd/conf.d/vhosts.conf" for the default setup mentioned in other instructions here).
- Add the "AddOutputFilterByType DEFLATE text/html text/plain text/xml" Filter to each virtual host (virtual hosts are the groupings starting with "<VirtualHost "). You should inclose the filter in a conditional module statement ("") to make sure your web server keeps running even if you happen to remove the deflate module.
- Save the virtual hosts configuration file.
- Open the SSH client and transfer to the root user ("sudo su")
- Restart the apache2 service ("service httpd restart").
The changes to the virtual hosts configuration file
- <VirtualHost *:80>
- ....
- <IfModule mop_deflate.c>
- AddOutputFilterByType DEFLATE text/html text/plain text/xml
- </IFModule>
- ...
- </VirtualHost>
Summary of command line inputs
- $ sudo su
- $ service httpd restart