Slow download for dotnet-runtime-wasm-*

[joelverhagen]

I just wanted to post this just in case someone else was encountering this problem. I'm following these steps:
https://github.com/unoplatform/Uno.Wasm.Bootstrap/blob/main/doc/using-the-bootstrapper.md#how-to-use-the-bootstrapper-with-net-5-and-later

The download from this URL appears to be very slow.
https://unowasmbootstrap.azureedge.net/runtime/dotnet-runtime-wasm-windows-585dcd7-7db1c333330-4019238418-Release.zip

I can reproduce it from my web browser. A HEAD request is fast but the GET request stalls out around 17 MB then again at 28 MB (after several attempts). The build log shows this:

Downloading dotnet-runtime-wasm-windows-585dcd7-7db1c333330-4019238418-Release to C:\Users\joelv\AppData\Local\Temp\dotnet-runtime-wasm-windows-585dcd7-7db1c333330-4019238418-Release.zip

The HEAD request returns this:

HTTP/1.1 200 OK
Connection: keep-alive
Content-MD5: 32HN0TAxoMKVcOUtkSd0JQ==
Vary: Origin
x-ms-request-id: d7996a73-401e-003e-2936-38f85b000000
x-ms-version: 2009-09-19
x-ms-lease-status: unlocked
x-ms-blob-type: BlockBlob
x-azure-ref: 20230204T012114Z-6mr927xff506781kevffdb7cys00000000eg00000000tnr5
X-Cache: TCP_HIT
Accept-Ranges: bytes
Content-Length: 50432215
Content-Type: application/zip
Date: Sat, 04 Feb 2023 01:21:14 GMT
ETag: 0x8DAFFE9B1C14CA4
Last-Modified: Thu, 26 Jan 2023 22:07:20 GMT

The TCP_HIT seems to indicate that the CDN (Microsoft CDN from Azure?) has the response body cached but it's still slow.

After waiting some time, the download in Visual Studio build output shows this:

Retrying... (An exception occurred during a WebClient request.)

Unsurprisingly the Azure Status page shows no issue: https://status.azure.com/en-us/status.

Update: my geo is Ohio, USA. I am reproducing this issue at 8:28 PM Eastern Standard Time, 2023-02-03.

[joelverhagen]

The Linux URL stalls out around 24 MB:
https://unowasmbootstrap.azureedge.net/runtime/dotnet-runtime-wasm-linux-585dcd7-7db1c333330-4019238418-Release.zip

The Windows -threads URL stalls out around 16 MB:
https://unowasmbootstrap.azureedge.net/runtime/dotnet-runtime-wasm-windows-585dcd7-7db1c333330-4019238418-Release-threads.zip

The Windows -simd URL stalls out around 8 MB:
https://unowasmbootstrap.azureedge.net/runtime/dotnet-runtime-wasm-windows-585dcd7-7db1c333330-4019238418-Release-simd.zip

[joelverhagen]

As a side note, this could perhaps be packaged as a NuGet package to avoid your own CDN/bandwidth costs.