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Top 10 Azure Functions Anti-Patterns

Disaster happens for Azure Functions. Ive often come across suboptimal practices related to Azure Functions. To streamline the information, Ive highlighted the top 10 Azure Functions anti-patterns. My hope is that by shedding light on these common missteps, you can design better Azure Functions and prevent potential system outages or inconsistent behavior in your applications. 1. Overriding Azure Functions Host Functionality (C#). Its important to note that overriding the Azure Functions Host functionality isnt supported. Many might be unaware of the repercussions of this anti-pattern. Consider the following example in Startup.cs: This snippet essentially overrides the native Azure Functions capabilities, which can lead to unintended behaviors.Example 1: Overriding Authentication Logic. The following code snippet, from Startup.cs, attempts to override Azures default authentication logic:// BAD CODEpublic override void Configure(IFunctionsHostBuilder builder) {...}By adopting such an approach, you risk undermining the core functionalities of Azure Functions. To elaborate, this action interferes with the authentication logic that Azure uses to validate requests from internal microservices.Example 2: Overriding IConfiguration. Overriding IConfiguration can render Azure Functions Host ineffective. The below code showcases this anti-pattern: // BAD CODE public class Startup : FunctionsStartup {...}Contrarily, refer to the Azure Functions documentation on customizing configuration sources. Heres the correct way to update IConfiguration:// GOOD CODEpublic class Startup : FunctionsStartup{ // Use ConfigureAppConfiguration for update IConfiguration public override void ConfigureAppConfiguration(IFunctionsConfigurationBuilder builder) {...} public override void Configure(IFunctionsHostBuilder builder) {...}}Isolated Worker Overrides. Similar missteps can occur with dotnet-isolated. Heres a problematic example:// BAD CODEvar host = new HostBuilder() ...This code often results in exceptions that terminate the isolated process, making diagnosis chall