Apache rate limiting
This is a fork of mod_qos found at http://mod-qos.sourceforge.net/
The purpose of this fork is to return a HTTP response code of 429 instead of 500 when a connection is dropped, due to too many concurrent connections.
For example limiting the number of concurrent requests to the /api url to 6. This is placed in the http.conf file of apache. Normally when more than 6 requests were received a HTTP 500 was given, but instead a 429 is now given in this fork.
<IfModule mod_qos.c>
# limits concurrent requests to the locations:
# - /api max. 6 concurrent requests
QS_LocRequestLimit /api 6
</IfModule>