Hi, On Thu, Jan 21, 2010 at 05:01:24PM +0800, Delta Yeh wrote: > Hi, > I use nginx + haproxy , in one box , to load balance 4 web server. > The load is about 5000 request/second for haproxy. > Sometimes there is tcp port is not available error.
This is not normal. This probably means that your TCP stack is not correctly tuned. TCP allows you to have up to 64k source ports to establish an outgoing connection. I think you're far below that at 5k requests/s. Also, recent versions of haproxy let you use one full source port range per server. This was needed because some people on the list run with 150k concurrent connections ;-) > Does haproxy support listening on unix domain socket, so ,in theory, we > won't have such error again? It does only for the stats right now, but it should be fairly easy to enable this for HTTP too. I wanted to extend the "bind" statement to support unix-domain socket paths, but this remained very low in my priority list. I know that David Birdsong (CCed) was interested in this too, though I don't know if he had any time to look at that. > And does anyone compare local loop tcp connection against unix socket under > linux? What do you mean precisely ? The only real advantage I see to unix sockets right now is that they don't require IP:ports, which make it possible to chain multiple components more easily, without having to worry about what port may be used. Also, unix sockets do not support splicing under linux, which means that we can't use kernel zero-copy optimizations to forward data, and we must copy it ourselves using the standard recv/send() method. If you want to release your TCP source ports faster, you can also enable the "nolinger" option on the server side (so in the backend only and not in the frontend nor the defaults section). Regards, Willy
