protected function maybeAddServerConnections()
    {
        if (!$this->enabled) {
            return; // Not possible.
        }
        if ($this->serversDiffer()) {
            $this->Pool->quit();
            $this->Pool->resetServerList();

            $this->Pool->setOption(\Memcached::OPT_NO_BLOCK, true);
            $this->Pool->setOption(\Memcached::OPT_LIBKETAMA_COMPATIBLE, true);

            if (\Memcached::HAVE_IGBINARY) { // Size and speed gains.
                $this->Pool->setOption(\Memcached::OPT_BINARY_PROTOCOL, true);
                $this->Pool->setOption(\Memcached::OPT_SERIALIZER, \Memcached::SERIALIZER_IGBINARY);
            }
            $this->Pool->setOption(\Memcached::OPT_CONNECT_TIMEOUT, 1000);
            $this->Pool->setOption(\Memcached::OPT_POLL_TIMEOUT, 1000);
            $this->Pool->setOption(\Memcached::OPT_RETRY_TIMEOUT, 1);

            $this->Pool->setOption(\Memcached::OPT_SEND_TIMEOUT, 1000000);
            $this->Pool->setOption(\Memcached::OPT_RECV_TIMEOUT, 1000000);

            $this->Pool->addServers($this->servers);
        }
    }