Effective Logging Strategies in ASP.NET Core

In ASP.NET Core, you can configure logging levels to control the verbosity of logs across your application and third-party frameworks.

A common pattern is to set a default minimum log level (e.g., Warning) and enable verbose logging (Trace) only for your own application namespace.

Example configuration in appsettings.json or an environment-specific file:

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning",
      "Microsoft": "Warning",
      "System": "Warning",
      "YourAppNamespace": "Trace"
    }
  }
}

• "Default": "Warning" sets a baseline for all logs.
• "Microsoft" and "System" are explicitly set to Warning to reduce noise from framework logs.
• "YourAppNamespace": "Trace" enables detailed logging for your application code.

This ensures your app logs detailed information while keeping system logs concise and manageable.

ASP.NET Core allows you to customize logging behavior per provider, such as Console or Application Insights. This is useful when you want different verbosity or volume controls depending on the sink.

Example:

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning",
      "Microsoft": "Warning",
      "System": "Warning",
      "YourAppNamespace": "Trace"
    },
    "Console": {
      "LogLevel": {
        "Default": "Information",
        "YourAppNamespace": "Debug"
      }
    },
    "ApplicationInsights": {
      "LogLevel": {
        "Default": "Error"
      }
    }
  }
}

• Console logs are more verbose for development and debugging (Information and Debug).
• Application Insights only logs errors to reduce telemetry volume and cost.

Use per-provider overrides when you want finer control over logging destinations.

It’s best practice to tailor logging levels per environment (Development, Staging, Production) by using environment-specific configuration files like appsettings.Development.json or appsettings.Production.json.

Example for Development (verbose logging):

{
  "Logging": {
    "LogLevel": {
      "Default": "Debug",
      "Microsoft": "Information",
      "System": "Warning",
      "YourAppNamespace": "Trace"
    }
  }
}

Example for Production (concise logging):

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning",
      "Microsoft": "Warning",
      "System": "Warning",
      "YourAppNamespace": "Information"
    }
  }
}

By adjusting log levels per environment, you can capture detailed diagnostics during development while reducing noise and performance impact in production.