On Tue, Feb 02, 2016 at 01:21:52PM -0800, Alfred Perlstein wrote: > >>> I would second John's comment on the necessity of the change though, > >>> if one already have 32K of *backlogged* connections, it's probably not > >>> very useful to allow more coming in. It sounds like the application > >>> itself is seriously broken, and unless expanding the field have some > >>> performance benefit, I don't think it should stay. > >> Imagine a hugely busy image board like 2ch.net, if there is a single > >> hiccup, it's very possible to start dropping connections. > > In reality start dropping connections in any case: nobody will be > > infinity wait of accept (user close browser and go away, etc). > > > > Also, if you have more then 4K backloged connections -- you have > > problem, you can't process all connections request and in next second > > you will be have 8K, after next second -- 12K and etc. > >
> In our case the user would not really know if our "page" didn't load > because we were just an invisible gif. > > So back to the example, let's scale that out to today's numbers. > > 100mbps -> 10gigE, so that would be 1500 conn/sec -> 150,000 conn/sec. > so basically at 0.20 of a second of any sort of latency I will be > overflowing the listen queue and dropping connections. OK, you talk about very specilal case -- extremaly short connections, about one data packet. Yes, in this case you got this behaivor. I think case of 2ch is different. > Now when you still have CPU to spare because connections *are* precious, > then the model makes sense to slightly over-provision the servers to > allow for somebacklog to be processed. > > So, in today's day and age, it really does make sense to allow for > buffering more than 32k connections, particularly if the developer knows > what he is doing. > > Does this help explain the reasoning? Yes, some special cases may be exist. _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
