Configuration

haproxy.cfg

1.4.x

% cat /etc/haproxy/haproxy.cfg
global
        log 127.0.0.1   local0
        maxconn 4096
        uid 99
        gid 99
        daemon
        #debug
        #quiet
        stats socket /tmp/haproxy.sock user root group wheel level admin

defaults
        log     global
        mode    http
        option  httplog
        option  dontlognull
        option  redispatch
        retries 3
        maxconn 2000
        contimeout      5000
        clitimeout      50000
        srvtimeout      50000

listen  app-cluster 0.0.0.0:9000
        cookie  SERVERID rewrite
        balance roundrobin
        server  app1 127.0.0.1:9001 cookie app1 check inter 5000
        server  app2 127.0.0.1:9002 cookie app2 check inter 5000

% service haproxy check
% service haproxy start

Unix Socket Commands

• http://cbonte.github.io/haproxy-dconv/configuration-1.4.html#9.2

You can manage the status of haproxy via the UNIX domain socket.

% cat /etc/haproxy/haproxy.cfg
global
        ...
        stats socket /tmp/haproxy.sock user root group wheel level admin
...

The command socat helps us do that.

% yum install socat

% echo "show info" | socat stdio /tmp/haproxy.sock
% echo "disable server app-cluster/app1" | socat stdio /tmp/haproxy.sock
% echo "enable server app-cluster/app1" | socat stdio /tmp/haproxy.sock

# or use interactive mode
% socat readline /tmp/haproxy.sock
prompt
> help
...