Introduction

This action leverages steadybit/failure-azure-functions-net and the Azure App Configuration to inject latency into an Azure Function or ASP.NET application.

Use Cases

• Understand how an Azure Function or ASP.NET application behaves when it experiences latency.

Prerequisites

Azure Functions

Azure Function must be using v4 isolated worker model and .NET 8 or higher.

Azure Function must be wrapped with the Steadybit Injection Middleware.

Please note that multiple parallel failure injections on the same azure function are not supported.

ASP.NET

ASP.NET application must use .NET 8 or higher.

ASP.NET application must be wrapped with the Steadybit Injection Middleware.

Important Considerations

The default implementation of the Azure App Configuration middleware in .NET is non-blocking. Therefore, the configuration refresh does not occur in the request where refresh started; instead, it is active from that request onward. In Azure Functions, this might present itself as flaky due to how the Azure Function Consumption Plan operates, which reuses instances with the previous state (you need one request beforehand to get the refreshed configuration).

Parameters

Parameter	Description	Default
Duration	The duration of the attack.	30s
Rate	The rate of invocations to affect. (100 = all request, 50 = half of all requests)	100%
Minimum Latency	Minimum latency to inject.	500ms
Maximum Latency	Maximum latency to inject.	500ms