> But there are some cases, such as when serving audio/video streams (looking at you, porn :) where the server will send its response straight to the user, not back through the load balancer. So, the load balancer doesn't know how busy the server is, unless that information is communicated separately, through some other channel.
Loadbalancer can still see it's an incoming connection as long as user is sending something (even if returning traffic goes directly) so at the very least it can keep number of connections same.
Of course one might stream 240p while other user streams 4k but for example in HAProxy there is an option to use external agent for health checks, that also have option to modify traffic weights and cut traffic to ones that are being swamped
Loadbalancer can still see it's an incoming connection as long as user is sending something (even if returning traffic goes directly) so at the very least it can keep number of connections same.
Of course one might stream 240p while other user streams 4k but for example in HAProxy there is an option to use external agent for health checks, that also have option to modify traffic weights and cut traffic to ones that are being swamped