go循环发送http请求经常报错超时

代码如下：

func NewHttping(method, protocol string, timeoutDuration time.Duration) *Httping {
	return &Httping{
		Method:   method,
		Protocol: protocol,
		Client:	  &http.Client{
			Timeout: timeoutDuration,
			Transport: &http.Transport{
				TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
			},
		},
	}
}

func (httping *Httping) Ping(t model.TargetIp) (float64, *http.Response, error) {
	var resp *http.Response
	var body io.Reader
	if httping.Method == "POST" {
		body = bytes.NewBufferString("{}")
	}
	req, err := http.NewRequest(httping.Method, fmt.Sprintf("%s://%s:%d", httping.Protocol, t.IP, t.Port), body)
	if t.Header != "" {
		head := map[string]interface{}{}
		err := json.Unmarshal([]byte(t.Header), &head)
		if err != nil {
			seelog.Error("[func:httping is err]", err.Error())
		}
		for key, val := range head {
			req.Header.Add(key, val.(string))
		}
	}
	if err != nil {
		return 0, nil, err
	}

	duration, errIfce := utils.TimeIt(func() interface{} {
		resp, err = httping.Client.Do(req)
		return err
	})
	if errIfce != nil {
		err := errIfce.(error)
		return 0, nil, err
	}
	return duration, resp, nil
}

报错信息如下：

2019-05-13/18:15:03 [Error] httping.go [func:HTTP StartPing ] www.youku.com - failed: Get http://www.youku.com:80: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)

我这边设置的超时时间是10s，程序以间隔2秒的时间差循环发送求情，但是经常报错超时，我想着youku不至于这样吧，麻烦大神帮我看看问题出在什么地方了吗