Thanks, Kip, good to know. I partly understand what you said, especially the last sentence, which I rather like.
As a next step I should ask the TCP cognoscenti if this kind of tuning is as wise as I imagine. Tom On 5/28/11 9:09 AM, "K. Macy" <km...@freebsd.org> wrote: >Unfortunately msl is a global variable: > >tcp_timer.c: > >int tcp_msl; >SYSCTL_PROC(_net_inet_tcp, OID_AUTO, msl, CTLTYPE_INT|CTLFLAG_RW, > &tcp_msl, 0, sysctl_msec_to_ticks, "I", "Maximum segment lifetime"); > > >Sockets or rather inpcbs in timewait are maintained on a per-vnet >list. Since tcp_twstart is called from tcp_do_segment in tcp_input.c >it does actually have access to the mbuf triggering the state >transition and thus the receiving interface. As far as I can tell, >changing the behavior to what you're asking for would not be >difficult. > > >Cheers, >Kip > >On Fri, May 27, 2011 at 4:59 PM, Tom Worster <f...@thefsb.org> wrote: >> [[I asked this yesterday on -questions, probably the wrong list]] >> >> If a server has one interface to the Internet and another interface to a >> switch connecting to a few other servers, it seems TCP's MSL value might >> reasonably be set a lot lower on the private interface. >> >> I'm specifically thinking of a lot of short MySQL connections(*) between >> the >> servers on the private LAN. The average number of MySQL client >>connections >> in TIME_WAIT will be proportional to MSL. And, while the circumstances >> under which a long MSL would help anything are unimaginable on the LAN, >> they are not on the Internet. >> >> So can net.inet.tcp.msl be set per interface? >> >> (*) Or similar: Sphinx, memcached, perhaps. >> >> Tom >> >> >> >> _______________________________________________ >> freebsd-net@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-net >> To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org" >> _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
