On Mon, Apr 13, 2015 at 6:09 PM, Lukas Tribus <luky...@hotmail.com> wrote:
> > On Mon, Apr 13, 2015 at 4:58 PM, Lukas Tribus > > <luky...@hotmail.com<mailto:luky...@hotmail.com>> wrote: > >> Hi, > >> > >> I'm experiencing latency problems while running HAProxy 1.4.18. > >> > >> Our backend servers reply to HAProxy almost instantly (~4ms), but some > >> of those replies are sent to the clients more than 100ms later. > >> > >> We have approx. 50k sessions opened at any time, with a HTTP request > >> coming in approximately every minute over each session. > > > > I suggest you try "option http-no-delay" but really try to understand > > the implications: > > > http://cbonte.github.io/haproxy-dconv/configuration-1.4.html#option%20http-no-delay > > > > > > > Thanks Lucas, "option http-no-delay" seems to have solved the problem. > > Good, but this will just hide the real problem and may cause others (as > per the documentation). > Both 1.4.23 and 1.4.20 fix latency (MSG_MORE/DONTWAIT) related problems, > also, if you always > expect zero latency from the proxy then you are misusing HTTP. > > I strongly suggest you consider upgrading to latest stable (either 1.4 or > better yet 1.5) and retry > without this command. > > You didn't provide your configuration so its not possible to tell if your > are running into those > already fixed bugs, or if you simply need zero latency in all cases per > application design. > Thank you for your suggestions, I'll discuss upgrading with our sysops team. Unfortunately misusing HTTP keep-alive is what we do ;-) We're running a real-time bidding system which has to reply to auctions (HTTP GET or POST requests) over thousands of connections within 75ms. Each connection doesn't carry much traffic, maybe one request per minute, and both the requests and our replies are very small. Waiting for a full reply packet will never work in our case. It would be much more efficient to decrease the number of concurrent connections and send requests more often, but unfortunately we have no control over this. Best regards, -- *Michał Ślizak* DaftCode Sp. z o.o. ul. Domaniewska 34a, 02-672 Warszawa tel. +48 506 175 074
