Strategies for Handling Large File Uploads in a .NET Web API?

Question

I am designing a .NET Web API that needs to handle large file uploads. I am exploring different strategies to efficiently process and store large files while ensuring the application remains responsive. Can anyone provide insights, recommendations, or resources on handling large file uploads in a .NET Web API?

Answer 1

For handling large file uploads, implement streaming to process files as they are uploaded, avoiding storing the entire file in memory. Use multipart/form-data encoding for file data. Implement file chunking to upload large files in smaller parts. Set appropriate timeouts and memory limits, and consider using a CDN or blob storage for offloading large files. Monitor resource usage and optimize as needed.

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Answer 2

I've manned several api backend apps and speaking from experience the best way to handle this is to stream it directly to its destination (avoid caching locally), this reduce memory consumption drastically!

short example:

[HttpPost("Upload")]
public async Task<IActionResult> Upload()
{
    var stream = Request.Body;
    using (var fileStream = new FileStream("destinationPath", FileMode.Create))
    {
        await stream.CopyToAsync(fileStream);
    }
    return Ok();
}

Things that definitely need to be added are: (rated by importance)

1. Error Handling: By far this is the most important and i mean it. Create a method to log any error you encounter to a log file, use try,catch and other methods to avoid your code from just crashing.
2. Chunking: Im not sure what type of data you're dealing with but consider splitting it into several pieces. This helps you take into consideration possible network failure which might cause the "big" type of file to suddenly corrupt..
3. Rate Limiting & Throttling: Implement rate limiting and throttling mechanisms to prevent the server from being overwhelmed by too many large file uploads simultaneously, i.e Sleep timers.
4. Timeout Handling: As part of the error handling it is very important to adjust the timeout settings on both the client and server sides to prevent issues during large uploads.

Consider viewing:

• Upload files in ASP.NET Core: https://learn.microsoft.com/en-us/aspnet/core/mvc/models/file-uploads?view=aspnetcore-5.0
• Hangfire: https://www.hangfire.io/

I believe you will find HAngfire very useful for this type of jobs!

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if you found this helpful, please mark as the answer. This took some time to put together so I'm hoping you found it useful.