On Thu, 2 May 2024 at 15:22, Roberto Carna <robertocarn...@gmail.com> wrote: > > Dear all, I have HAproxy in front of a web server node. > > I want the web server node to accept just 1000 concurrent connections. > > So I want to use the maxconn parameter in order to let new connections > above 1000 to wait until the web service has free workers. > > According to what I read, if I define maxconn in frontend section of > haproxy.cfg, the incoming connections above 1000 will wait in the > kernel socket queue, and if I define the parameter in the backend > section the connections above 1000 will wait in the web server node > until there are workers free. > > So where is the best section to define the maxconn parameter???
If you want to limit the connections to a server, that's is exactly where you put the limit: *server* maxconn There is no "backend" maxconn, it's always defined per server. Leave more room in the frontend, e.g. 2000 or 3000 and set global maxconn way above the total amount of connections (considering both front and backend/server connections (like 10000 in this example). This way, haproxy handles the queuing. If you leave that up to the kernel, haproxy will not see the connections above this threshold at all. No logging, no stats, and you may even loose access to the haproxy stats interface, if it is on the same frontend. Lukas
