True Zero Downtime HAProxy Reloads

Created on 2023-02-05T17:29:09-06:00

Create a "plug" qdisc queue in Linux.
Create an iptables rule to route all TCP SYN requests to the queue.
Plug the queue when you are about to do a reload; incoming requests will now back up in memory.
Reload your daemon.
Unplug the queue and incoming requests will begin processing immediately.