dg00GT00 / concurrent-requests-with-httpclient

Example code for https://makolyte.com/csharp-how-to-make-concurrent-requests-with-httpclient/

The purpose of this repo is to help you run example code from this article: https://makolyte.com/csharp-how-to-make-concurrent-requests-with-httpclient/

There are two apps:

1. /client/ - this is a console app that executes concurrent requests to the service stub found in /service/.
2. /server/ - this is an ASP.NET web API service stub with a single endpoint: GET /RandomNumber/. This runs as a console app, so you can see the requests coming in.

The service stub runs on https://localhost:12345/.

To run (happy path)

1. Start the ASP.NET web API project in /server/.
2. Run the console app in /client/

You should see it send 15 requests concurrently without problems.

To see the error handling

The simplest way to induce errors is to not even run the service stub endpoint. When requests are sent, they'll fail with a "Connection refused" socket error.

1. Don't run the ASP.NET web API. Or stop it if it's already running.
2. Run the console app in /client/

You should see 15 requests concurrently. It throttles, so only 4 are actually sent concurrently. You'll see 1 request fail and trip the circuit. The 3 that were being sent at the same time will fail. The remaining 11 will all not even attempt to send since the circuit is tripped.

To see timeouts

The simplest way to simulate timeouts is to use toxiproxy. See here: https://makolyte.com/how-to-use-toxiproxy-to-verify-your-code-can-handle-timeouts-and-unavailable-endpoints/

Alternatively, you could add an endpoint to the service stub that does: await Task.Delay(-1, HttpContext.RequestAborted)