sysctl kern.ipc.somaxconn limit 65535 why?

Garrett Cooper yanegomi at gmail.com
Wed Oct 3 22:27:21 UTC 2012


On Wed, Oct 3, 2012 at 3:03 PM, Ryan Stone <rysto32 at gmail.com> wrote:
>>> Or the TTL of TCP connections might be too high for the volume of
>>> connections received. Someone else on net@ reported that changing
>>> this value to more aggressively reap sockets improved performance
>>> greatly (at the cost that more connections potentially needing to
>>> be reestablished and/or getting dropped on the floor if things go
>>> too high volume).
>>
>> That's a different topic I think.  On busy web servers it's fairly
>> typical to have a lot of TCP sockets staying in TIME_WAIT state for
>> extended time and the usual tuning would be to set MSL to about 2
>> seconds at the expense of sacrificing slow clients who can't make
>> 3-way handshake in time (*), etc.  The TTL of IP packet have nothing
>> to do with this though, and our default (64) is saner than many other
>> operating systems.
>
> Presumably RTT was meant here instead of TTL.

    Yes, I screwed up my nomenclature and TIME_WAIT was what I was
trying to note.
Thanks!
-Garrett


More information about the freebsd-current mailing list