大并发开启13000个协程post调用微信接口但是有将近1万个返回err:i/o timeout，怎么减少这种状况是访问微信大都成功

具体微信返回错误： Post https://api.weixin.qq.com/cgi-bin/message/wxopen/template/send?access_token=WbydbNY8e6B2UHhaI0EliHR-bPav66gwsr0Gwka0nggTnRRSwLHh_4TwaFuQLM6DCsi3pAxfl3TaR85fblxTVwSbQVuWS4l9AF3KJPZcjyNvdOX7XA9EBQqs8yCndAR_YJKbAEANYZ: dial tcp: lookup api.weixin.qq.com on 119.29.29.29:53: dial udp 119.29.29.29:53: i/o timeout post代码： c := &http.Client{ // Timeout: 10 * time.Second, Transport: &http.Transport{ Dial: (&net.Dialer{ Timeout: 2 * time.Second, KeepAlive: 2 * time.Second, }).Dial, TLSHandshakeTimeout: 2 * time.Second, ResponseHeaderTimeout: 2 * time.Second, ExpectContinueTimeout: 2 * time.Second, }, } res, err := c.Post(url, "application/json", body)