Lukas Tribus wrote: > > On Wed, 10 Feb 2021 at 16:55, Victor Sudakov <[email protected]> wrote: > > > > I can even phrase my question in simpler terms. What happens if the sum > > total of all servers' maxconns in a backend is less than the maxconn > > value in the frontend pointing to the said backend? > > Queueing for "timeout queue" amount of time, and then return 503 error
And what happens in TCP mode, after the "timeout queue" amount of time? I suppose the TCP connection with the client is reset? > > See: > > timeout queue > https://cbonte.github.io/haproxy-dconv/2.2/configuration.html#4.2-timeout%20queue > > maxconn > https://cbonte.github.io/haproxy-dconv/2.2/configuration.html#5.2-maxconn > > > I really suggest you ignore minconn and fullconn, and focus on maxconn > instead. The latter is a must-have (and must-understand). Really > maxconn (global, frontend and per server ) is the single most > important performance knob in haproxy. Maxconn is rather clear, especially when one is sure about two things: 1. A server's maxconn value is always a hard limit (notwithstanding if there is a minconn configured for the server). 2. Connections outnumbering the sum total of a backend's servers maxconns are queued for the "timeout queue" amount of time and then dropped. Are the above statements correct? It would be nice however to understand minconn/fullconn too. If a backend has several servers with identical minconn, maxconn and weight, what's the point of having minconn? The load will be always distributed evenly between all the servers notwithstanding minconn/fullconn, correct? -- Victor Sudakov, VAS4-RIPE, VAS47-RIPN 2:5005/49@fidonet http://vas.tomsk.ru/
