Asp net core unexpected exception in iishttpserver handlerequest

Introduction

ASP.NET is a popular programming language used for building web applications. It provides a framework for developing dynamic websites, web services, and web applications. However, like any other programming language, ASP.NET can encounter unexpected exceptions during runtime. In this article, we will explore how to handle unexpected exceptions in ASP.NET Core when running on IIS.

Understanding the Exception

When an unexpected exception occurs in an ASP.NET Core application running on IIS, it is important to understand the root cause of the exception. This can be done by examining the exception details, including the exception message, stack trace, and any inner exceptions. These details can provide valuable insights into the source of the problem.

Logging the Exception

Logging the exception is crucial for troubleshooting and debugging purposes. ASP.NET Core provides a built-in logging framework that can be used to log exceptions. By logging the exception, you can capture important information such as the time of occurrence, the specific error message, and the stack trace. This information can be used to identify the cause of the exception and take appropriate actions to resolve it.

try
{
    // Code that may throw an exception
}
catch (Exception ex)
{
    // Log the exception
    logger.LogError(ex, "An unexpected exception occurred");
}

Handling the Exception

Once the exception is logged, it is important to handle it gracefully to prevent the application from crashing or displaying an error page to the user. ASP.NET Core provides various mechanisms for handling exceptions, such as custom error pages, exception filters, and global exception handling.

Custom Error Pages

Custom error pages allow you to display a user-friendly error page when an exception occurs. This can be achieved by configuring the UseExceptionHandler middleware in the Startup.cs file. The middleware catches any unhandled exceptions and redirects the user to the specified error page.

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    // Other middleware configurations

    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseExceptionHandler("/Home/Error");
    }

    // Other middleware configurations
}

Exception Filters

Exception filters allow you to handle exceptions at the controller or action level. By applying an exception filter attribute to a controller or action method, you can catch specific exceptions and perform custom actions, such as logging, redirecting, or returning a specific response.

[TypeFilter(typeof(CustomExceptionFilter))]
public class HomeController : Controller
{
    // Controller actions
}

public class CustomExceptionFilter : IExceptionFilter
{
    private readonly ILogger logger;

    public CustomExceptionFilter(ILogger logger)
    {
        this.logger = logger;
    }

    public void OnException(ExceptionContext context)
    {
        // Log the exception
        logger.LogError(context.Exception, "An unexpected exception occurred");

        // Perform custom actions, such as redirecting or returning a specific response
        context.Result = new RedirectToActionResult("Error", "Home", null);
    }
}

Global Exception Handling

Global exception handling allows you to handle exceptions at the application level. By configuring the UseExceptionHandler middleware in the Startup.cs file, you can catch any unhandled exceptions and perform custom actions, such as logging, redirecting, or returning a specific response.

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    // Other middleware configurations

    app.UseExceptionHandler("/Home/Error");

    // Other middleware configurations
}

Conclusion

Handling unexpected exceptions in ASP.NET Core when running on IIS is crucial for maintaining the stability and reliability of your web application. By understanding the exception, logging it, and handling it gracefully, you can ensure a better user experience and simplify the troubleshooting process. Whether you choose to use custom error pages, exception filters, or global exception handling, it is important to have a robust exception handling strategy in place.