On Thu, Apr 7, 2022 at 9:57 AM Dave Taht <dave.t...@gmail.com> wrote:
> Most cloud operations websites are kept internal. gitlab's is not, > which is pretty cool. In looking over this issue, today: > > https://gitlab.com/gitlab-com/gl-infra/production/-/issues/6768 > > They are tracking tcp syn retransmits, but not drops or other > congestion control related info. And > also using: > > sysctl net.ipv4.tcp_notsent_lowat=4294967295; > > where we've been getting good results with that set as low as 32k. > Anyone know anyone at gitlab? > It looks like that's their current setting, but the test they're running will be to drop it to 16K: sysctl net.ipv4.tcp_notsent_lowat=16384; It'll be interesting to see what the results of the test are, and whether 16K becomes the new "normal" for them. :) (cool to see this--I spent a certain amount of my time at my previous job doing kernel parameter tuning for large scale services, so seeing what values others are testing with is good validation. :) Matt
