Should I use for .NET Logging in Azure: AddAzureWebAppDiagnostics or AddApplicationInsights?

Question

I'd like to have custom logging in my code, which will be hosted in Azure. I've found two extensions for logging providers, between which I am not sure what is the difference.

The two providers that I'm using in my program.cs:

builder.Logging.AddAzureWebAppDiagnostics();
builder.Logging.AddApplicationInsights();

I tried to comment either and in Azure's logs the trace is still the same. Any idea what is the difference between the two and which one should I stick to?

Answer 1

builder.Logging.AddAzureWebAppDiagnostics();

• By using AddAzureWebAppDiagnostics Method, we can add an Azure Diagnostics logger and can get the diagnostic logs in Azure App Service.

• we need to configure file logger options in Program.cs file.

• Install the NuGet Package Microsoft.Extensions.Logging.

• In Program.cs file, add the below lines of code to configure diagnostic logs.

using Microsoft.Extensions.Logging.AzureAppServices;
builder.Logging.AddAzureWebAppDiagnostics();
builder.Services.Configure<AzureFileLoggerOptions>(options =>
{
    options.FileName = "Diagnostics-Logs";
    options.FileSizeLimit = 50 * 1024;
    options.RetainedFileCountLimit = 3;
});

• Build and deploy the App to Azure App service.
• In Azure App service => App Service Logs => enable Application logging (Filesystem).

• After enabling the filesystem, In Kudu console logs are created in a new file under D:\home\LogFiles\Application path.

builder.Logging.AddApplicationInsights();

AddApplicationInsights() method is to configure Application Insights for Azuer App Service.

• Install the NuGet package Microsoft.Extensions.Logging.ApplicationInsights.
• AddApplicationInsights() requires LogLevel .It is not mentioned,by default it takes LogLevel.Warning.

In Program.cs file, add the below code.

using Microsoft.Extensions.Logging.ApplicationInsights;
builder.Logging.AddApplicationInsights();

Controller

 [HttpGet(Name = "GetWeatherForecast")]
        public IEnumerable<WeatherForecast> Get()
        {
            _logger.LogTrace("Trace Log");
            _logger.LogDebug("Debug Log");
            _logger.LogInformation("Information Log");
            _logger.LogWarning("Warning Log");
            _logger.LogError("Error Log");
            _logger.LogCritical("Critical Log");

            return Enumerable.Range(1, 5).Select(index => new WeatherForecast
            {
                Date = DateTime.Now.AddDays(index),
                TemperatureC = Random.Shared.Next(-20, 55),
                Summary = Summaries[Random.Shared.Next(Summaries.Length)]
            })
            .ToArray();
        }

Application Insights

References taken from AddAzureWebAppDiagnostics and AddApplicationInsights