Date: Tue, 05 Nov 2019 19:28:41 -0600 From: Mike Karels <mike@karels.net> To: "Jose G. Juanino" <jjuanino@gmail.com> Cc: freebsd-stable@freebsd.org Subject: Re: High Send-Q values in netstat after upgrading to 12.1-RELEASE: system is unusable Message-ID: <201911060128.xA61SfVr065464@mail.karels.net> In-Reply-To: Your message of Wed, 06 Nov 2019 00:37:50 %2B0100. <20191105233750.4nojttru53i2j6cc@riemann.ust-global.com>
next in thread | previous in thread | raw e-mail | index | archive | help
> On Tuesday, November 05 at 22:44:10 CET, Jose G. Juanino wrote: > > Hi all, > > = > > today I have upgraded to 12.1-RELEASE from 12.0-RELEASE-p10 via > > freebsd-update. The host is a VMware guest with vmx net interface. The > > system runs with 12.0-RELEASE perfectly, with no issue, reliably for m= onths. > > = > > I have boot environments enabled (thanks god) and therefore I am able = to > > switch between both 12.0 and 12.1 versions. > > = > > Just after boot the new 12.1 release, I noticed that my apache did not > > serve pages with the previous speed, but rather the opposite: any web > > operation from clients hangs. > > = > > After a single inspection in the FreeBSD 12.1 server, I see that Send-= Q > > in netstat is the root cause of the issue. While in 12.0 Send-Q is > > almost always zero or close to zero in every socket, in 12.1 I get the > > following (snipped output): > > > > [ .... ] > > > Hi again, after doing a further research, I have noticed that in 12.0 > version dev.vmx.0.txq0.hstats.tso_packets is always increasing > (especially when doing large transfers), but in 12.1 is statically equal > to zero, never increases. > As workaround, I have disabled TCP segment offloading by setting the > net.inet.tcp.tso=3D0 sysctl in 12.1 version and the host again performs > almost as well as before in 12.0. Have you tried disabling jumbo rather than TSO? If jumbo is enabled on this system, but not on the client (or next hop), all the segments sent from the server that are over 1500 bytes will be lost, and data will pile up in the send queue waiting for acknowledgement. > I hope this helps others suffering the same issue. > Regards > -- = > Jose G. Juanino Mike
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201911060128.xA61SfVr065464>