> ## Documentation Index
> Fetch the complete documentation index at: https://ancplua.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# AL0077 - Duplicate instrumentation detected

> Both auto and manual instrumentation creates duplicate spans

Source: [Al0077DuplicateInstrumentationAnalyzer.cs](https://github.com/ANcpLua/ANcpLua.Analyzers/blob/main/src/ANcpLua.Analyzers/Analyzers/Al0077DuplicateInstrumentationAnalyzer.cs)

## Description

Using both automatic instrumentation (e.g., `AddAspNetCoreInstrumentation()`) and manual spans for the same operation creates duplicate traces.

## Bad Code

```csharp theme={null}
builder.Services.AddOpenTelemetry()
    .WithTracing(t => t
        .AddAspNetCoreInstrumentation()
        .AddSource("MyService"));
// Then also manually creating spans in middleware for HTTP requests
```

## Good Code

```csharp theme={null}
builder.Services.AddOpenTelemetry()
    .WithTracing(t => t
        .AddAspNetCoreInstrumentation()
        .AddSource("MyService.Custom")); // Only custom spans
```

## Properties

* **Category**: OpenTelemetry
* **Severity**: Warning
* **Enabled by default**: True
* **Code fix available**: False

## Configuration

```editorconfig theme={null}
dotnet_diagnostic.AL0077.severity = warning
```