Buffering issues with nginx

[Dan34]

I wrote my own proxy and it appears that the data is all stuck in socket
buffers. If SNDBUF isn't set, then OS will resize it if you try to write
more data than remote can accept. Overall, in my tests I see that this
buffer grows to 2.5MB and in wireshark I see that difference grows up to
5MB. As docs from SO_SNDBUF state, actual internal value is usually twice
larger than what SO_SNDBUF ports then it kind of starts to make sense where
this max 5MB difference is wasted.

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,275526,275635#msg-275635