> On Jun 29, 2018, at Jun 29, 5:11 AM, Leela Kalidindi (lkalidin) > <[email protected]> wrote: > > Hi, > > How can I enforce haproxy to reuse limited backend connections regardless of > number of client connections? Basically I do not want to recreate backend > connection for every front end client. > > "HAPROXY_0_BACKEND_HEAD": "\nbackend {backend}\n balance {balance}\n mode > http\n option httplog\n option forwardfor\n option http-keep-alive\n option > persist\n http-reuse aggressive\n maxconn 16\n", > "HAPROXY_0_FRONTEND_HEAD": "\nfrontend {backend}\n bind > {bindAddr}:{servicePort}\n mode http\n option httplog\n option > forwardfor\n option http-keep-alive\n maxconn 16\n" > > I currently have the above configuration, but still backend connections are > getting closed when the next client request comes in. > > Could someone help me with the issue? Thanks in advance! >
I suspect that there is a misunderstanding of what backend connection re-use means. Specifically this portion from the documentation seems to trip people up: https://cbonte.github.io/haproxy-dconv/1.8/configuration.html#http-reuse <https://cbonte.github.io/haproxy-dconv/1.8/configuration.html#http-reuse> No connection pool is involved, once a session dies, the last idle connection it was attached to is deleted at the same time. This ensures that connections may not last after all sessions are closed. I suspect that in your testing, you send one request, observe TCP state, then send a second request and expect the second request to use the same TCP connection. This is not how the feature works. The feature is optimized to support busy / loaded servers where the TCP open rate should be minimized. This allows a server to avoid, say opening 2,000 new connections per second, and instead just keep re-using a handful. It’s not a connection pool that pre-opens 10 connections and keeps them around in case they might be needed. -Bryan
