The config listen option rcvbuf which maps to the TCP SO_RCVBUF, is applied to the listening socket, and not inherited by the accept()ed connections. So if you have a high load application where the legitimate request is bound to be no more than 4K, for instance, you could save a lot of RAM by dropping the default here without changing it at the system level.

I straced nginx and it does not seem to actually apply the settings through a subsequent setsockopt to the accepted socket. Is this intentional or an oversight?

Thanks in advance.

Ata Roboubi