#haproxy has some excellent http ratelimit traffic shaping features #linuxstr #techstr
In the backend section where you would like to enable the limit:
    add a filter bwlim-out directive to limit download speeds
    add a filter bwlim-in directive to limit upload speeds
backend webservers
  server web1 192.168.56.6:80 check maxconn 30
  server web2 192.168.56.7:80 check maxconn 30         
  filter bwlim-out mydownloadlimit limit 625000 key be_id table mypeers/downloadrate         
  filter bwlim-in myuploadlimit limit 625000 key be_id table mypeers/uploadrate
  http-response set-bandwidth-limit mydownloadlimit 
  http-request set-bandwidth-limit myuploadlimit
dig their KB doc for more ... this is microblog tip only