This score tracks your application's upload performance, which affects both the upload speed and the performance impact of uploads to the rest of your application.

ASP.NET uploads are resource intensive, and can rapidly degrade overall application performance due to thread pool exhaustion, and high cpu, memory, and disk usage.

How this score is calculated

The score tracks upload duration, sizes, and rates, as well as whether uploads are blocking requests.

The score decreases to 0% as upload blocking time approaches total request execution time for the application. In order to improve the score, upload times and upload blocking must be reduced.


We will automatically identify a number of upload-related issues that can affect application performance, including:

  • Slow uploads, possibly caused by slow or malicious clients.

  • Very large uploads, which can take a long time to complete and can have severe performance impact on memory and disk.

  • Blocking uploads, which can tie up request threads and cause thread pool exhaustion/hangs for the rest of the application.

The causes will identify the location of the problematic uploads in your application, and allow you to dig deeper into specific request traces.

Improving this score

Applications that handle large, slow, or a high volume of uploads, often experience poor performance and lowered upload speeds as workload increases. This is due to a complex interplay of factors including thread pool demands of longer uploads, memory cost of buffering uploaded data, and disk usage necessary to save the incoming data.

To drastically improve upload speeds and overall application performance, consider LeanSentry ScaleUP: the only high-performance upload engine available for the IIS/ASP.NET platform.

ScaleUP transparently replaces the default upload mechanism with a highly optimized upload engine that can handle thousands of concurrent uploads, with minimized application impact and drastically improved upload speeds.

ScaleUP has been successfully deployed by high upload volume sites including VEVO, MySpace, and LeanSentry itself. Learn more ->

More resources

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