protected function querySentinelForSlaves(NodeConnectionInterface $sentinel, $service)
    {
        $slaves = array();

        $payload = $sentinel->executeCommand(
            RawCommand::create('SENTINEL', 'slaves', $service)
        );

        if ($payload instanceof ErrorResponseInterface) {
            $this->handleSentinelErrorResponse($sentinel, $payload);
        }

        foreach ($payload as $slave) {
            $flags = explode(',', $slave[9]);

            if (array_intersect($flags, array('s_down', 'o_down', 'disconnected'))) {
                continue;
            }

            $slaves[] = array(
                'host' => $slave[3],
                'port' => $slave[5],
                'alias' => "slave-$slave[1]",
            );
        }

        return $slaves;
    }