Date: Sat, 19 Mar 2011 16:13:55 -0700 From: Navdeep Parhar <nparhar@gmail.com> To: George Neville-Neil <gnn@neville-neil.com> Cc: arch@freebsd.org Subject: Re: Updating our TCP and socket sysctl values... Message-ID: <AANLkTi=ptv617t0KhgNrcxTUzLmQd0eLFBf2x4%2BP7EAL@mail.gmail.com> In-Reply-To: <132388F1-44D9-45C9-AE05-1799A7A2DCD9@neville-neil.com>
index | next in thread | previous in thread | raw e-mail
On Fri, Mar 18, 2011 at 11:37 PM, George Neville-Neil <gnn@neville-neil.com> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Howdy, > > I believe it's time for us to upgrade our sysctl values for TCP sockets so that > they are more in line with the modern world. At the moment we have these limits on > our buffering: > > kern.ipc.maxsockbuf: 262144 > net.inet.tcp.recvbuf_max: 262144 > net.inet.tcp.sendbuf_max: 262144 > > I believe it's time to up these values to something that's in line with higher speed > local networks, such as 10G. Perhaps it's time to move these to 2MB instead of 256K. > > Thoughts? 256KB seems adequate for 10G (as long as the consumer can keep draining the socket rcv buffer fast enough). If you consider 2 x bandwidth delay product to be a reasonable socket buffer size then 256K allows for 10G networks with ~100ms delays. Normally the delay is _way_ less than this for 10G and even 256K may be an overkill (but this is ok, the kernel has tcp_do_autorcvbuf on by default) While we're here discussing defaults, what about nmbclusters and nmbjumboXX? Now those haven't kept up with modern machines (imho). Regards, Navdeephome | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?AANLkTi=ptv617t0KhgNrcxTUzLmQd0eLFBf2x4%2BP7EAL>