HaProxy (cannot bind socket, select test failed) - sockets

Question

Hello everyone,
Im working about an high availbility project, I had to put in production an haproxy for some applications. Everything was ok after some basics tests but I had some errors and cant fix it. Does someone have some ideas ?
here is the test
# /usr/sbin/haproxy -d -f /etc/haproxy/haproxy.cfg
Available polling systems :
sepoll : pref=400, test result OK
epoll : pref=300, test result OK
poll : pref=200, test result OK
select : pref=150, test result FAILED
Total: 4 (3 usable), will use sepoll.
Using sepoll() as the polling mechanism.
[ALERT] 174/160258 (22038) : Starting proxy mysql: cannot bind socket
[ALERT] 174/160258 (22038) : Starting proxy http: cannot bind socket
There is my file haproxy.cfg
global
log 127.0.0.1 local0 notice
user haproxy
group haproxy
maxconn 32000
ulimit-n 65536
defaults
log global
option dontlognull
retries 2
timeout connect 3000
timeout server 5000
timeout client 5000
option redispatch
listen mysql
bind *:3306
mode tcp
option tcplog
balance roundrobin
option mysql-check user haproxy_check
server mysql1 10.83.83.167:3306 check
server mysql2 10.83.83.168:3306 check
server mysql3 10.83.83.169:3306 check
listen http
mode http
bind *:80
stats enable
stats uri /stats
stats auth admin:HaProxy2014
acl app1_cluster_acl hdr_beg(host) -i app1
acl app2_cluster_acl hdr_beg(host) -i app2
acl mysql_cluster_acl hdr_beg(host) -i mysql
use_backend app1_cluster if app1_cluster_acl
use_backend app2_cluster if app2_cluster_acl
use_backend mysql_cluster if mysql_cluster_acl
backend app1_cluster
mode http
cookie SERVERID insert indirect nocache
option forwardfor header X-Real-IP
option http-server-close
option httplog
balance roundrobin
server serv1 10.83.83.203:80 check cookie serv1
server serv2 10.83.83.204:80 check cookie serv2
backend app2_cluster
mode http
cookie SERVERID insert indirect nocache
option forwardfor header X-Real-IP
option http-server-close
option httplog
balance roundrobin
server serv1 10.83.83.187:80 check cookie serv1
server serv2 10.83.83.188:80 check cookie serv2
backend mysql_cluster
mode http
cookie SERVERID insert indirect nocache
option forwardfor header X-Real-IP
option http-server-close
option httplog
balance roundrobin
server mysql1 10.83.83.167:80 check cookie serv1
server mysql2 10.83.83.168:80 check cookie serv2
server mysql3 10.83.83.169:80 check cookie serv2

Answer 1

I get the same error if there is already a mysql or http service running on my load balancer in addition to ruuning on the back ends.
For example if nginx/apache is already running on my load balancer.
$ netstat -anp | grep ":80"
tcp 0 0 127.0.0.1:80 0.0.0.0:* LISTEN 3646/nginx
And i try to start my load balancer with bind *:80 i get a similar error.
$ haproxy -d -f /etc/haproxy/haproxy.cfg
Available polling systems :
epoll : pref=300, test result OK
poll : pref=200, test result OK
select : pref=150, test result FAILED
Total: 3 (2 usable), will use epoll.
Using epoll() as the polling mechanism.
[ALERT] 195/001456 (1903) : Starting frontend www: cannot bind socket [0.0.0.0:80]
If you need to have a mysql or http instance listening on 127.0.0.1 then you can specify the ip of another interface in the bind call.
bind: 10.0.0.20:80
With the latest version of haproxy you can now even use variables.
bind ${LB1}:80
And export these from the haproxy startup script or /etc/default/haproxy
export LB1="10.0.0.20"
Otherwise perhaps there is an issue with your haproxy startup scripts.