将文件上传到 Azure 存储时出错

Question

我正在将网站从标准 ASP.NET 网站转换为使用 Azure。该网站之前已获取管理员用户上传的 Excel 文件并将其保存在文件系统中。作为迁移的一部分，我将此文件保存到 Azure 存储。通过 Azure SDK 对我的本地存储运行时，它运行良好。 （我正在使用 1.3 版本，因为我不想在开发过程中升级。）

但是，当我将代码指向 Azure 存储本身时，该过程通常会失败。我得到的错误是： 发生 System.IO.IOException

  Message=Unable to read data from the transport connection: The connection was closed.
  Source=Microsoft.WindowsAzure.StorageClient
  StackTrace:
       at Microsoft.WindowsAzure.StorageClient.Tasks.Task`1.get_Result()
       at Microsoft.WindowsAzure.StorageClient.Tasks.Task`1.ExecuteAndWait()
       at Microsoft.WindowsAzure.StorageClient.CloudBlob.UploadFromStream(Stream source, BlobRequestOptions options)
       at Framework.Common.AzureBlobInteraction.UploadToBlob(Stream stream, String BlobContainerName, String fileName, String contentType) in C:\Development\RateSolution2010\Framework.Common\AzureBlobInteraction.cs:line 95
  InnerException: 

代码如下：

public void UploadToBlob(Stream stream, string BlobContainerName, string fileName,
        string contentType)
    {
        // Setup the connection to Windows Azure Storage
        CloudStorageAccount storageAccount = CloudStorageAccount.Parse(GetConnStr());

        DiagnosticMonitorConfiguration dmc = DiagnosticMonitor.GetDefaultInitialConfiguration();
        dmc.Logs.ScheduledTransferPeriod = TimeSpan.FromMinutes(1);
        dmc.Logs.ScheduledTransferLogLevelFilter = LogLevel.Verbose;
        DiagnosticMonitor.Start(storageAccount, dmc);      
        CloudBlobClient BlobClient = null;
        CloudBlobContainer BlobContainer = null;
        BlobClient = storageAccount.CreateCloudBlobClient();

        // For large file copies you need to set up a custom timeout period
        // and using parallel settings appears to spread the copy across multiple threads
        // if you have big bandwidth you can increase the thread number below
        // because Azure accepts blobs broken into blocks in any order of arrival.
        BlobClient.Timeout = new System.TimeSpan(1, 0, 0);
        Role serviceRole = RoleEnvironment.Roles.Where(s => s.Value.Name == "OnlineRates.Web").First().Value;
        BlobClient.ParallelOperationThreadCount = serviceRole.Instances.Count;  

        // Get and create the container
        BlobContainer = BlobClient.GetContainerReference(BlobContainerName);
        BlobContainer.CreateIfNotExist();

        //delete prior version if one exists
        BlobRequestOptions options = new BlobRequestOptions();
        options.DeleteSnapshotsOption = DeleteSnapshotsOption.None;
        CloudBlob blobToDelete = BlobContainer.GetBlobReference(fileName);
        Trace.WriteLine("Blob " + fileName + " deleted to be replaced by newer version.");
        blobToDelete.DeleteIfExists(options);

        //set stream to starting position
        stream.Position = 0;
        long totalBytes = 0;
        //Open the stream and read it back.
        using (stream)
        {
            // Create the Blob and upload the file
            CloudBlockBlob blob = BlobContainer.GetBlockBlobReference(fileName);
            try
            {
                BlobClient.ResponseReceived += new EventHandler<ResponseReceivedEventArgs>((obj, responseReceivedEventArgs)
                =>
                {
                    if (responseReceivedEventArgs.RequestUri.ToString().Contains("comp=block&blockid"))
                    {
                        totalBytes += Int64.Parse(responseReceivedEventArgs.RequestHeaders["Content-Length"]);
                    }
                });                 
                blob.UploadFromStream(stream);
                // Set the metadata into the blob
                blob.Metadata["FileName"] = fileName;
                blob.SetMetadata();
                // Set the properties
                blob.Properties.ContentType = contentType;
                blob.SetProperties();
            }
            catch (Exception exc)
            {
                Logging.ExceptionLogger.LogEx(exc);
            }
         }
     }

我已尝试对代码进行多种不同的更改：在替换之前删除 blob（尽管问题也存在于新 blob 上）、设置容器权限、不设置权限等。

Answer 1

您的代码看起来应该可以工作，但它具有许多并非严格要求的额外功能。我会把它减少到绝对最低限度，然后从那里开始。这真的只是一种直觉，但我认为这可能是让你悲伤的使用语句。这个enture函数可以写成（假设容器已经存在）：

public void UploadToBlob(Stream stream, string BlobContainerName, string fileName,
                string contentType)
            {
                // Setup the connection to Windows Azure Storage
                CloudStorageAccount storageAccount = CloudStorageAccount.Parse(GetConnStr());
                CloudBlobClient BlobClient = storageAccount.CreateCloudBlobClient();
                CloudBlobContainer BlobContainer = BlobClient.GetContainerReference(BlobContainerName);
                CloudBlockBlob blob = BlobContainer.GetBlockBlobReference(fileName);
                stream.Position = 0;
                blob.UploadFromStream(stream);
            }

关于我删除的内容的注释：

• 您应该只在应用程序启动时设置一次诊断，而不是每次调用方法时。通常在 RoleEntryPoint.OnStart()
• 如果您有更多实例，我不确定您为什么要尝试将ParallelOperationThreadCount 设置得更高。这两件事似乎无关。
• 每次向其中保存内容时检查容器/表是否存在并不是一种好方法。通常在您的应用程序启动时进行一次检查，或者在网站外部有一个进程以确保所有必需的容器/表/队列都存在。当然，如果您尝试动态创建容器，则并非如此。

Answer 2

问题出在我笔记本电脑上的防火墙设置上。这是我最初在家中设置的个人笔记本电脑，因此没有为公司环境设置防火墙规则，导致上传和下载性能下降。