My adventures into retro gaming have brought me back into the semi-seedy world of piracy websites and the technology considerations that dictate their business model. Annoying popups and pornographic advertisements aside, the most obvious technological observation I made was that each of these sites used bandwidth throttling as a way to make money. Want that game to download quickly? Stump up $10 per month and it will be lightning fast; otherwise you’re relegated to sleep-inducing download speeds.
In researching download speed limits, it became apparent that dynamic rate limitation is incredibly inefficient, and that the best way to throttle downloads is by configuring different servers or virtual directories with different download speeds, and directing each user to each server based on the download speed they should have.
Configuring Apache’s Download Speed Limit
To throttle the download speed on Apache servers, enable the
<!-- Requires 2.4+ --> LoadModule ratelimit_module modules/mod_ratelimit.so
Then set different download speeds by directory with the following Apache configuration:
<IfModule mod_ratelimit.c> <!-- 100kb/second limit --> <Location /tier1> SetOutputFilter RATE_LIMIT SetEnv rate-limit 100 </Location> <!-- 500kb/second limit --> <Location /tier2> SetOutputFilter RATE_LIMIT SetEnv rate-limit 500 </Location> </IfModule>
Some type of dynamic Apache config would allow custom URLs per user which would obscure download speed URLs so users couldn’t dynamically spoof URLs to get some else’s download speed.
The download speed limit and throttling business seems booming: just look at MEGA and other likewise services. The science behind download throttling is big business and I hope to learn more about it. In the mean time, it’s nice to know that download speed limitation can be done with a few Apache directives!