HAproxy configuration file rebinding

Question

Is it possible for HAproxy to reload its configuration at runtime, without dropping existing connections?

I've looked high and low in the documentation for some mention of this but have been unsuccessful. Does anybody know off hand?

Thanks.

Answer 1

I am not sure about how perfectly this handles a reload, but the command line option for this to haproxy is -sf:

-sf Send FINISH signal to the pids in pidlist after startup. The processes which receive this signal will wait for all sessions to finish before exiting. This option must be specified last, followed by any number of PIDs. Technically speaking, SIGTTOU and SIGUSR1 are sent.

This is what the reload argument does in my Ubuntu init scripts:

haproxy_reload()
{
        $HAPROXY -f "$CONFIG" -p $PIDFILE -D $EXTRAOPTS -sf $(cat $PIDFILE) \
                || return 2
        return 0
}