.net core Task.Result Wait等造成502

这两天公众号项目上线，刚开始项目运行没什么问题，但几天之后，访问量激增，服务器崩溃了，每次请求都返回502，一脸懵逼，无从下手，赶紧开日志里的BUG，拿出来一个个改，BUG都改完之后，没有明显的效果，赶紧网上找资料，找了很多找到了这个罪魁祸首，就是Task.Result，原因如下。

IIS连接池连接数有限，高并发的情况下多余的请求会处于排队状态，特别是Task.Result会阻塞请求线程，造成了IIS线程池的资源浪费，解决方案，使用异步接口async/await，这样会很快的释放请求线程，节约资源。

例如：

        [HttpGet, HttpAuth(false)]
        public async Task<IActionResult> GetWeChatInfo(string code)
        {

            #region 获取openid
            string url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=wx3e&secret=7c61&code=" + code + "&grant_type=authorization_code";
            string result =await HttpUtil.GetData(url);
            var openInfo = JsonConvert.DeserializeAnonymousType(result, new { access_token = "", refresh_token = "", expires_in = 0, openid = "", scope = "" });

            string urlStr2 = "https://api.weixin.qq.com/sns/userinfo?access_token=" + openInfo.access_token + "&openid=" + openInfo.openid + "&lang=zh_CN";
            string result2 = await HttpUtil.GetData(urlStr2);
            var userinfo = JsonConvert.DeserializeAnonymousType(result2, new { openid = "", nickname = "", sex = 1, language = "", city = "", province = "", country = "", headimgurl = "", privilege = new List<dynamic>() });
            #endregion

            #region 根据openid获取是否关注公众号
            string urlA = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=wx3&secret=7c6";
            string resultA = await HttpUtil.GetData(urlA);
            var openInfoA = JsonConvert.DeserializeAnonymousType(resultA, new { access_token = "" });

            string urlStrB = "https://api.weixin.qq.com/cgi-bin/user/info?access_token=" + openInfoA.access_token + "&openid=" + userinfo.openid + "&lang=zh_CN";
            string resultC = await HttpUtil.GetData(urlStrB);
            #endregion

            var userInfoJson = JObject.Parse(resultC);
            return Success(userInfoJson);

        }

参考链接：

https://q.cnblogs.com/q/106342/

https://www.cnblogs.com/farb/p/5014773.html

https://www.cnblogs.com/vipyoumay/p/5663950.html