HAProxy Sticky Sessions Node.js iOS Socket.io - ios

Question

I am trying to implement sticky sessions with HAProxy.
I have a HAProxy instance that routes to two different Node.js servers, each running socket.io. I am connecting to these socket servers (via the HAProxy server) using an iOS app (https://github.com/pkyeck/socket.IO-objc).
Unlike when using a web browser, the sticky sessions do not work, it is like the client is not handling the cookie properly and so the HAProxy server just routes the request to wherever it likes. Below you can see my HAProxy config (I have removed the IP addresses):
listen webfarm xxx.xxx.xxx.xxx:80
mode http
stats enable
stats uri /haproxy?stats
stats realm Haproxy\ Statistics
stats auth haproxy:stats
balance roundrobin
#replace XXXX with customer site name
cookie SERVERID insert indirect nocache
option httpclose
option forwardfor
#replace with web node private ip
server web01 yyy.yyy.yyy.yyy:8000 cookie server1 weight 1 maxconn 1024 check
#replace with web node private ip
server web02 zzz.zzz.zzz.zzz:8000 cookie server2 weight 1 maxconn 1024 check
This is causing a problem with the socket.io handshake, because the initial handshake routes to server1 then subsequent heartbeats from the client go to server2. This causes server2 to reject the client because the socket session ID is invalid as far as server 2 is concerned, when really all requests from the client should go to the same server.

Answer 1

Update the haproxy config file /etc/haproxy/haproxy.cfg by the following:
global
daemon
maxconn 256
defaults
mode http
timeout connect 5000ms
timeout client 50000ms
timeout server 50000ms
frontend http-in
bind *:80
default_backend servers
option forwardfor
backend servers
cookie SRVNAME insert
balance leastconn
option forwardfor
server node1 127.0.0.1:3001 cookie node1 check
server node2 127.0.0.1:3002 cookie node2 check
server node3 127.0.0.1:3003 cookie node3 check
server node4 127.0.0.1:3004 cookie node4 check
server node5 127.0.0.1:3005 cookie node5 check