EDIT

The production server frequently is brought to its limit by clients sending as too many request per second

Solutions:

1. either production server is not capable to handling enough request per second
2. we need to throttle the connection rate per seconds per IP addess

This post provides a good introduction into the topic of connection rate limiting by making use of iptables: https://making.pusher.com/per-ip-rate-limiting-with-iptables/