[fidz]

I wonder, how does nginx and haproxy handle long/persistent connection session? The connection itself can't be terminated since there is actual client, established connection with a backend beneath. Will the reload be failed? (Something like, "connection termination timeout; can't reload; try later"). For web workers probably we won't see this; for most of the time, the connection is terminated after request done.

[jolynch]

Both NGINX and HAProxy will hang around for as long as the connection is open (up to the timeout). It's actually quite an issue when you're rapidly reloading either proxy (you can run out of memory reasonably easily), but most services that have long lived TCP connections also handle resets reasonably well so you can typically just kill the old proxies and it'll be ok.

[r4um]

There is an option added in 1.7 which makes old process exit after a grace period https://cbonte.github.io/haproxy-dconv/1.7/configuration.htm...