异步方法在多个图像上传时首先失败运行

Question

我有一个摄影师可以上传照片的网站。该站点托管在共享的 Azure Web 应用程序上，照片和照片的缩略图上传到 Azure Blob 存储，并将记录写入数据库。摄影师一次最多可以上传 700mb 的照片。

我的问题

我有一个同步上传方法，A) 花了很长时间运行和 B) 失败并显示 "There is not enough space on disk" 错误消息。我猜这是因为 Azure 共享 Web 应用程序的临时文件夹限制为 200mb。

我试图实现一个异步方法来帮助加快上传速度，但它成功地完成了第一张照片（即存在 blob 和数据库记录），然后它似乎只是挂起。这是我第一次尝试编写异步方法。

我也不知道如何解决临时文件夹大小问题。

我的调用方式

    public static async Task<Tuple<bool, string>> UploadAsync(HttpPostedFileBase[] photos, Bookings booking, string photoType, ApplicationUser user)
    {

        // For each file to be uploaded
        foreach (HttpPostedFileBase file in photos)
        {
            try
            {
                await UploadPhotoFromFileAsync(file, user, booking.BookingsId, photoType);

            }
            catch (Exception ex)
            {
                // Not Implemented
            }
        }

        return new Tuple<bool, string>(true, "Photos uploaded successfully");
    }

我的照片上传方法

    public static Task UploadPhotoFromFileAsync(HttpPostedFileBase file, ApplicationUser user, int bookingId, string photoType)
    {
        return Task.Run(() =>
        {
            using (ApplicationDbContext dbt = new ApplicationDbContext())
            {
                Bookings booking = dbt.Bookings.Find(bookingId);

                // Craete a new record in the UserFiles table
                Photos photo = new Photos();
                photo.BookingsId = booking.BookingsId;
                photo.PhotoType = photoType;
                photo.FileName = Path.GetFileName(file.FileName);

                string confirmedDate = string.Empty;
                if (booking.ConfirmedDate.HasValue)
                {
                    DateTime actualConfirmedDate = booking.ConfirmedDate.Value;
                    confirmedDate = actualConfirmedDate.Year.ToString() + actualConfirmedDate.Month.ToString() + actualConfirmedDate.Day.ToString();
                }

                string blobName = string.Empty;
                string blobThumbName = string.Empty;
                if (photoType == "SamplePhoto")
                {
                    // Get the count of the sample photos in the gallery 
                    List<Photos> samplePhotos = dbt.Photos.Where(m => m.BookingsId == booking.BookingsId && m.PhotoType == "SamplePhoto").ToList();

                    blobName = "TS_" + booking.location.Location.Replace(" ", "") + "_" + booking.BookingsId.ToString() + "_" + confirmedDate + "_" + (samplePhotos.Count).ToString() + "_sample" + Path.GetExtension(file.FileName);
                    blobThumbName = "TS_" + booking.location.Location.Replace(" ", "") + "_" + booking.BookingsId.ToString() + "_" + confirmedDate + "_" + (samplePhotos.Count).ToString() + "_sample_thumb" + Path.GetExtension(file.FileName);
                }
                else
                {
                    // Get the count of the sample photos in the gallery 
                    List<Photos> photos = dbt.Photos.Where(m => m.BookingsId == booking.BookingsId && m.PhotoType == "GalleryPhoto").ToList();

                    blobName = "TS_" + booking.location.Location.Replace(" ", "") + "_" + booking.BookingsId.ToString() + "_" + confirmedDate + "_" + (photos.Count).ToString() + Path.GetExtension(file.FileName);
                    blobThumbName = "TS_" + booking.location.Location.Replace(" ", "") + "_" + booking.BookingsId.ToString() + "_" + confirmedDate + "_" + (photos.Count).ToString() + "_thumb" + Path.GetExtension(file.FileName);
                }

                // Create the Thumbnail image.
                CloudBlobContainer thumbnailBlobContainer = _blobStorageService.GetCloudBlobContainer("thumbnails");
                if (CreateThumbnailImageFromHttpPostedFileBase(file, blobThumbName, photo))
                {
                    photo.ThumbnailBlobName = blobThumbName;
                    photo.ThumbnailBlobUrl = thumbnailBlobContainer.Uri + "/" + blobThumbName;
                }

                CloudBlobContainer blobContainer = _blobStorageService.GetCloudBlobContainer("photos");
                photo.BlobName = blobName;
                photo.BlobUrl = blobContainer.Uri + "/" + blobName;

                photo.DateCreated = DateTime.Now;
                photo.CreatedBy = user.Id;

                dbt.Photos.Add(photo);
                dbt.SaveChanges();

                booking.Photos.Add(photo);
                dbt.SaveChanges();

                //Upload to Azure Blob Storage
                CloudBlockBlob blob = blobContainer.GetBlockBlobReference(blobName);
                blob.UploadFromStream(file.InputStream);
            }
        });
    }

Answer 1

Azure 存储库包括 Async-methods，您应该利用它们。而不是用 Task.Run 包装你的控制器方法，你可以使用 ASP.NET MVC's built-in async-capabilities.

所以，首先，使控制器的方法异步：

public async Task<ContentResult> UploadPhotoFromFileAsync...

然后删除所有 Task.Run。

最后，调用 Azure 存储库的 async-methods:

var blob = blobContainer.GetBlockBlobReference(blobName);
await blob.UploadFromStreamAsync(file.InputStream);

Answer 2

问题实际上是由 Web.Config 中设置的请求长度引起的。它不够高，无法上传照片的大小。我只是将以下代码添加到 Web.Config.

<system.web>
     <httpRuntime targetFramework="4.5" maxRequestLength="1048576" executionTimeout="900" />
</system.web>
<system.webServer>
    <modules>
        <remove name="FormsAuthentication" />
    </modules>
</system.webServer>

异步方法在多个图像上传时首先失败运行

Async method fails first run on multiple image upload

c#

asp.net-mvc

azure

asyncfileupload

异步方法在多个图像上传时首先失败 运行

Async method fails first run on multiple image upload

c#

asp.net-mvc

azure

asyncfileupload

异步方法在多个图像上传时首先失败运行