如何避免 Azure 函数中的线程重复？

Question

我在 Azure 函数中遇到线程重复问题。

该函数做了一些基本的事情：访问 SQL 数据库，调用一些 API 并完成执行。问题是：同一个 API 被多次调用。

行为如下：azure函数被队列触发，开始运行。它正确地开始执行，但过了一会儿，它会通过生成一个新的 Thd 并导致代码的所有剩余部分执行两次来复制它的执行。

我可以通过将函数设置为单例来解决它。这会起作用，但我需要并行执行，所以这不是一个选项。我需要的是让函数触发多次，但在内部它不会在两个线程中重复相同的执行。

我最初认为这是一个扩展问题：当流量很高时它会重复执行以获得更好的性能。但这不是真的：没有横向扩展触发器。

一些事实：

1. 我只在生产环境中遇到这个问题：我拥有的另外两个环境没有复制任何线程。生产的唯一区别是更好的 azure 订阅计划。
2. 横向扩展被禁用
3. 函数正常启动，最终生成两个线程。自执行一半以来，我可以看到双重日志。有时它会生成另一个属于另一个进程的线程。
4. 这不是每次都发生，而是在一个分组的时间段内。
5. 功能为.NET 3.1版本，应用服务计划为P1v2，与Web api应用共享。

        public void Run([QueueTrigger("testtest", Connection = "storageCnn")] string orderData)
        {
            try
            {
                _logger?.LogDebug($"{nameof(FunctionNAme)} created. DryRun = {_inDryRun}");
                _logger?.LogInformation($"Running {nameof(FunctionNAme)}...");

                //derserialize
                var tuple = JsonConvert.DeserializeObject<ExternalOrderDTO>(orderData);

                dynamic orderLineObj = LookupOrder(tuple.OrderLineId, tuple.ProductID);

                dynamic orderLine = orderLineObj.OrderLine;
                string cost = orderLineObj.Amount;
                string deviceId = orderLineObj.DeviceId;
                string paymentReference = orderLineObj.PaymentReference;

                _logger?.LogInformation($"loaded order from database = {orderLine != null}...");

                if (_inDryRun)
                {
                    //just return dummy values                 

                    Thread.Sleep(60000); // wait 1 minute for testing (simulating work)
                                         //set complete 
                    UpdateDB(orderLine, OrderStatus.Complete);

                    //inform payment webservice to check payment of parent order.
                    _wsHandler.InvokePaymentWS(orderLine.VOBEOrderLineId);

                    return;
                }

                _logger?.LogInformation("We are NOT in test-mode, continuing normal flow");

                //add to System A
                var systemaArticles = GetArticlesFromSystema();

                var articleId = MatchAndGetArticleId(systemaArticles, orderLine);
                string systemAOrderRef = AddOrderToSystemA(orderLine, articleId, cost, deviceId, paymentReference);
                _logger?.LogInformation($"systemA order Ref: {systemAOrderRef }");
                if (int.TryParse(systemAOrderRef, out int systemRef) && systemRef > 0)   //update status in database
                {
                    _logger?.LogInformation($"adding in DB : systemRef '{orderLine.ExternalOrderLineReference}', OrderLine: '{orderLine.Id}'");
                    orderLine.ExternalOrderReference = systemRef .ToString();
                    UpdateDB(orderLine, OrderStatus.Processing);

                    //wait for 2 sec.
                    _logger?.LogInformation("sleeping for 2 sec before reading the QR...");
                    Thread.Sleep(2000);

                    _logger?.LogInformation($"Reading the QR code of orderLine {orderLine.Id} on system...");
                    RunSystemReadingQRSequence(orderLine);
                }
                else
                    throw new Exception($"failed to get orderreference from system for VOBEOrder: {orderLine.VOBEOrderLineId}");
            }
            catch (Exception e)
            {
                _logger?.LogError($"Exception while executing {nameof(FunctionNAme)}. \n{e.Message}");
                _logger?.LogError(e.ToString());
                throw;
            }
        }

private void RunSystemReadingQRSequence(Entity orderLine)
        {
            try
            {
                _logger?.LogInformation($"asking System A for QR code of orderLine {orderLine.VOBEOrderLineId}");

                // call QR endpoint
                var qr = ReadQrFromSystemA(orderLine);

                // is no QR is received, it means something went wrong
                if (String.IsNullOrEmpty(qr))
                {
                    throw new Exception("failed to load the QR code. Returning msg to queue");
                }

                // if the value is present, store it in the DB
                _logger?.LogInformation($"saving the Qr code into the DB...");

                orderLine.QRCode = qr;
                UpdateDB(orderLine, OrderStatus.Complete);

                //inform payment webservice to check payment of parent order.
                _logger?.LogInformation($"informing payment webservice to check payment of parent order...");
                _wsHandler.InvokePaymentWS(orderLine.VOBEOrderLineId);
            }
            catch (Exception e)
            {
                _logger?.LogError($"Exception while asking System A QR code: {e.Message}");
                _logger?.LogError(e.ToString());
                throw new Exception("failed to load the QR code. Returning msg to queue");
            }
        }

 public void InvokePaymentWS(int orderLineId)
        {
            var req = WebRequest.CreateHttp(_url);
            req.AuthenticationLevel = AuthenticationLevel.None;
            req.Method = HttpMethods.Post;
            req.Headers.Add(HttpRequestHeader.ContentType, "application/json");
            req.Headers.Add("Authorization", "bearer {_key.Trim()}");

            try
            {
                using var stream = req.GetRequestStream();
                var bytes = Encoding.UTF8.GetBytes($"{{ \"orderLineId\": {orderLineId} }}");
                stream.Write(bytes, 0, bytes.Length);

                HttpWebResponse response = req.GetResponse() as HttpWebResponse;
                _logger?.LogInformation($"response from web service = {response.StatusCode}");
                if (response?.StatusCode == HttpStatusCode.Accepted)
                    _logger?.LogInformation("all good from WebsService calls");
            }
            catch (Exception ex)
            {
                _logger?.LogError(ex, ex.Message);

            }
        }

我试图避免横向扩展，但这不是问题