public function handler_read($id) {
        try {
            $this->lock_session($id);
            $sessiondata = $this->connection->get($id);
            if ($sessiondata === false) {
                $this->unlock_session($id);
                return '';
            }
            $this->connection->expire($id, $this->timeout);
        } catch (RedisException $e) {
            error_log('Failed talking to redis: '.$e->getMessage());
            throw $e;
        }
        return $sessiondata;
    }