Performance issue in UseProxyToSpaDevelopmentServer

[sdcb]

UseProxyToSpaDevelopmentServer causing a lot of time to forward the request.

The raw webpack/ng serve server is pretty fast, should be processed within 100ms, but UseProxyToSpaDevelopmentServer API have to wait for 4 seconds to handle this request.

To Reproduce

Create a angular SPA project (based on .NET Core 3.1), modify the Startup.cs, change UseAngularCliServer to UseProxyToSpaDevelopmentServer and hit Ctrl+F5 to run directly(and run ng serve in front-end folder at same time).

Checkout the browser F12, should see this:

When using raw webpack/ng serve command without proxy(http://localhost:4200), performance is much better:

Further technical details

• .NET Core 3.1/3.1.100
• Visual Studio 2019(16.4.2)

[sdcb]

Looks like the issue is related to this one: #16797

[pranavkm]

Do you know if the linked issue resolves your problem?

[sdcb]

@pranavkm I grab the latest code and does not seem help, it does not resolve my problem.

[pranavkm]

@javiercn this seems related to #18062.