Question: My Laravel 4 application's logs sometimes show a `NotFoundHttpException`:

```
exception 'Symfony\Component\HttpKernel\Exception\NotFoundHttpException' in /var/www/laravel4/bootstrap/compiled.php:7420
Stack trace:
#0 /var/www/laravel4/bootstrap/compiled.php(7137): Illuminate\Routing\Router->handleRoutingException(Object(Symfony\Component\Routing\Exception\ResourceNotFoundException))
#1 /var/www/laravel4/bootstrap/compiled.php(7113): Illuminate\Routing\Router->findRoute(Object(Illuminate\Http\Request))
#2 /var/www/laravel4/bootstrap/compiled.php(958): Illuminate\Routing\Router->dispatch(Object(Illuminate\Http\Request))
#3 /var/www/laravel4/bootstrap/compiled.php(946): Illuminate\Foundation\Application->dispatch(Object(Illuminate\Http\Request))
#4 /var/www/laravel4/public/index.php(49): Illuminate\Foundation\Application->run()
#5 {main}

```

What could have caused this? The stack trace doesn't show anything from my code.

Answer: 
A `NotFoundHttpException` is basically just a 404 in your application. Unfortunately the exception message doesn't even tell you the URL of the request that triggered the exception, which makes it difficult to understand these errors when you see them in your logs.

To give you more debugging information, set up your own 404 handler. Here's a simple handler which will log the URL (so you know what was requested to trigger the error) and the user agent (to help you figure out who or what made the request) and return a view and 404 code:

```
App::missing(function($e) {
    $url = Request::fullUrl();
    $userAgent = Request::header('user-agent');
    Log::warning("404 for URL: $url requested by user agent: $userAgent");
    return Response::view('errors.not-found', array(), 404);
});

```

Put it in `app/start/global.php`.
It's really hard to say for sure what is causing this without knowing your code. Looking at the stack trace of the error, it's clear that the Router is dispatching it and I guess it has nothing to do with the background job itself, but rather the API's it calls.

In your specific case, the exception is throw after a [ResourceNotFoundException](https://symfony2-document.readthedocs.org/en/latest/components/routing.html), which happens when there's no route defined for such URL pattern.

**Possible problems:**

If the background job does a `file_get_contents` or `curl` on your own API's, it may be calling a route that does not exist and then throwing that exception.

If you don't have control of the URL's the background job is downloading, it may be trying to fetch an URL like `127.0.0.1`, `localhost` or anything like that.