[Question] What is connection listen backlog?

[druchoo]

# -B connection listen backlog, defaults to 3
#143

currently the listen backlog is hardwired to 3, which isn't even near to sufficient on machines that handle 10K+ of connections per second, so we should be able to increase the backlog there.

This should allow resolving the
possible SYN flooding on port 2003. Sending cookies.
message

Can someone please explain what connection listen backlog is and elaborate on how changing this setting impacts performance?

[grobian]

I thought I answered this in length, apparently not.

long story short, the setting has no impact on performance.

[redbaron]

has it? setting it to 512 will do no harm whatsoever, but would make it more reliable against short burst of new incoming connections. setting it to 3 is just silly and have no reason to exist

[grobian]

If you want to advocate changing the default to 512, then go ahead, no reason not to change it if there is a good reason for it. File a new issue for it.

[druchoo]

My question has been answered and created #203 to increase default value to 512. Closing issue.

http://veithen.github.io/2014/01/01/how-tcp-backlog-works-in-linux.html for further reading on connection listen backlog