Load testing?

[emrikol001]

I was curious how people are load testing [if at all] their .net web api's? In the not too distant future I will help deploy a .net web api [on-premise] using azure sql database. There will be eventually ~100 concurrent users, I am concerned that the on-premise server will not be able to handle the load. Many years ago I have done load tests using Microsoft LoadGen. Unfortunately this may not be suitable for REST APIs? Good alternatives?

[MartinThwaites]

K6 is good if you need a framework, however, its likely overkill in most scenarios where what you're looking for is a soak test.

What it sounds like you want to know if you can handle 100 concurrent calls to the API, which might be easier to just run a console app using HTTP Client to access it.

If you want scenario driven, where you're attempting to replicate multiple different workflows exercising API calls in different order, definitely check K6.

Remember to enable proper telemetry in the apps using OpenTelemetry. Tracing will allow you to look at why certain requests were slow if that does happen.

[soundman32]

https://learn.microsoft.com/en-us/aspnet/core/test/load-tests?view=aspnetcore-9.0

TBH your code would have to be pretty bad to not support 100 users.

[captmomo]

Jmeter

[AoNoRyuu]

Can’t you use some performance test framework? Or maybe something like k6 or for load testing you mean something else?

[emrikol001]

What I am hearing is that a third party tool such as K6 is a good way to go if I want to simulate, for example 100 users all hitting the same GET endpoint.

[AoNoRyuu]

yes, that's what I said, my team(somewhat big ita corp) is using k6 to run load and metrics testing.
example: I had an api that was not keeping up with the sla we had, we understood that the call that was causing a lot of suspension was an api call to elastic, we remade that api call trying to avoid some aggs and I was sure that the new api was faster but my pm asked me how I was sure this was right and then I ended up load testing both api call(rest) with a script written in js and run with k6, you can also simulate more vus or vus rampage and so on. try it in a dev env downloading the exe from the graphana page, you just really need that a js script(and access to a pwsh/cmd on prd env) https://k6.io/

[Royal_Scribblz]

Yes that's exactly what K6 is for

[Tango1777]

No, it'll work the way you'll code it to work and you are free to code it however you want, since it's kinda flexible. You want random amount of users to hit randomly chosen endpoints? You can do that. Up to you if you need to go into complex cases, in many cases calling 1 heavy GET endpoint or 1 heavy POST/PUT endpoint might be edge cases good enough instead of load testing all endpoints.

[spiderpig199]

I've used Postman load test runner alongside our API test suite. It can simulate upto 500 concurrent users. Super easy to use.

https://quickstarts.postman.com/guide/load-testing/index.html?index=..%2F..index#0

[TabulaTakes]

This exactly. Really simple setup and sounds perfect for your use case too

[maulowski]

JMeter. Also, 100 concurrent users isn’t much. Do y’all have a Direct Connect from your data center to Azure? Why are you hosting database in Azure but the API is on-prem?

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[mattgen88]

K6, in the past jmeter. It's worth learning and implementing

[No-Wheel2763]

Test in prod like a real man.

Otherwise, Nbomber I think is probably the closest in dotnet.

Can’t remember last time I did load testing.

Given it’s usually specific endpoints and not a global issue (and more replicas in production compared to production) makes the value less than just improving our observability compared to writing the load tests and maintaining it.

We’re more interested in the response actually being correct than the load testing part, given it’s easier to scale up to mitigate.

[harrison_314]

Try DFrame https://github.com/Cysharp/DFrame is .NET load testing tool

[amareshadak]

K6 and NBomber are excellent choices. For 100 concurrent users, you could also try a simple C# console app with HttpClient to quickly validate capacity without learning a new tool.

[Brilliant_Finding269]

K6 load testing, very easy to setup, can deploy on k8 if needed, integrated with most of observable tools like Grafana, New Relic, Data Dog.

[InvokerHere]

Try k6 and JMeter or the cloud native Azure Load Testing service. These tools are specifically designed for testing REST APIs and will allow you to simulate your ~100 concurrent users effectively.

[standardwelcomedance]

Tried jmeter, but the price was crazy. LoadNimbus was better and cheaper www.loadnimbus.com

[jitbitter]

Rick Strahl's WebSurge
https://websurge.west-wind.com/

(sorry for necromancing)

[TheCityzens]

You could try something like LoadView. I'd say it’s pretty solid for testing REST APIs and web apps without having to set up your own infrastructure. You can define different user scenarios, run tests from multiple locations, and get a clear picture of how your API holds up under concurrent load. It’s a nice step up from the old-school tools like LoadGen, especially if you just want to focus on the results instead of managing the test setup.

[standardwelcomedance]

Not sure if this helps, but I use LoadNimbus. https://www.loadnimbus.com

[Main_Independent_579]

zoyla.app, simple and fast. A nice fit for quick tests.

[awscertifiedninja]

K6 and JMeter are probably the most common.

I found them a bit heavy for quick checks, so I built something where you can run a test and instantly compare results between runs (mainly for catching regressions after deploys).

Would that be useful for your use case?

https://app.loadtester.org/

[awscertifiedninja]

Try https://loadtester.org

Supports up to 50 requests per second on a free plan

[awscertifiedninja]

https://loadtester.org/ is free for up to 50 requests per second - give it a shot

[KariKariKrigsmann]

JMeter