Fixing “Laravel 11 Events Firing Multiple Times in Production” on Azure App Service

Fixing “Laravel 11 Events Firing Multiple Times in Production” on Azure App Service

At Neion Tech we often debug production-only issues that never appear on local machines.
In this article we’ll walk through a real case from Stack Overflow where a Laravel 11 application had events firing multiple times only in production (Nginx + Azure App Service, PHP 8.3) and how to fix it.

Original question on Stack Overflow:
Laravel 11 Events Firing Multiple Times in Production (Nginx, Azure App Services, PHP 8.3)

Scenario

Environment

• Laravel 11.x

• PHP 8.3

• Nginx

• Hosted on Azure App Services (one app for the main site, another for scheduled tasks)

An event is dispatched like this:

 

event(new ApplicationStatusChanged($application));

Locally everything works perfectly:

• One HTTP request → listener runs once.

In production, something strange happens:

• One POST request → listener runs twice (or more).

• The request itself is not duplicated.

• No queues are involved and no retries are happening.

So what’s going on?

 

Quick refresher: how Laravel 11 registers event listeners

Laravel 11 gives you two ways to connect events and listeners:

1. Automatic discovery (recommended)

   • By default Laravel scans the app/Listeners directory.

   • Any class there with a handle() or __invoke() method whose argument is type-hinted with an event will be registered automatically as a listener. Laravel+1

2. Manual registration

   • You can explicitly map events to listeners in code (e.g. via Event::listen() or configuration).

   • In older docs this was often done in EventServiceProvider, and from Laravel 11 onward you can also configure events via bootstrap/app.php. Laravel+1

Important detail:
If you both manually register a listener and let Laravel auto-discover it, that listener can be attached twice, so your event handler runs twice. This problem has even been discussed in framework issue trackers. GitHub

 

Root cause in the Stack Overflow case

After a lot of debugging, the root cause turned out to be:

1. There was a listener class in the default App\Listeners namespace with a handle() method for the event.

2. That same listener was also manually registered in the event configuration (e.g. in EventServiceProvider or via Event::listen).

3. The listener had a __construct() method, which contributed to some inconsistency between local and production discovery / caching.

Result:

• Locally: event discovery & caching were slightly different, so the duplication wasn’t obvious.

• Production (Azure): with optimizations and caches enabled, Laravel ended up registering the listener twice, so every time ApplicationStatusChanged was fired, the listener ran two times.

So the bug wasn’t in Azure, Nginx, PHP or the cron app at all – it was simply the listener being registered twice.

 

How to detect duplicate listeners

Here’s a small checklist you can use in any Laravel 11 app:

1. List all events and listeners

    

   php artisan event:list

   Look for the same listener class appearing more than once for the same event. Laravel+1

2. Search for manual registrations

   • Check bootstrap/app.php for withEvents(...). Laravel+1

   • Check any service providers (like AppServiceProvider) for Event::listen(...) calls.

3. Check your directories

   • If your listener lives in app/Listeners and has a handle() method, Laravel will auto-discover it.

   • If you also map it manually, you’ll get two registrations.

 

The fix

In the Stack Overflow case, the fix was straightforward:

1. Simplify the listener class

   • Remove any unnecessary __construct() logic if you don’t really need it.

   • Let the listener follow Laravel’s default pattern:

      

     namespace App\Listeners;

     use App\Events\ApplicationStatusChanged;

     class NotifySomethingAboutApplicationStatus { public function handle(ApplicationStatusChanged $event): void { // your logic here } }

2. Use one registration strategy only

   • Because the listener lives in App\Listeners and has a proper handle() method, we let Laravel auto-discover it.

   • We remove any manual registration of that listener from EventServiceProvider or Event::listen.

3. Clear and rebuild caches (important for production)

   During deployment to production, run:

    

   php artisan event:clear php artisan event:cache php artisan config:cache php artisan route:cache

   This ensures Laravel uses a clean manifest of events and listeners. Laravel+1

After these changes, both local and production environments behaved the same way and each event fired exactly once.

 

Best practices to avoid double-firing events in Laravel 11

Here are some recommendations we follow at Neion Tech:

1. Stick to conventions whenever possible

   • Put listeners in app/Listeners.

   • Name your handler method handle().

   • Rely on Laravel’s auto-discovery instead of manual wiring.

2. Avoid manual registration unless you really need it

   Only use Event::listen() or explicit mapping when:

   • listener lives outside the standard directory, or

   • you have a very custom architecture.

3. If you must register manually, move listeners out of app/Listeners

   For example, store them under app/Domain/Orders/Listeners and configure:

    

   // bootstrap/app.php return Application::configure(basePath: dirname(__DIR__)) -withRouting( web: __DIR__.'/../routes/web.php', commands: __DIR__.'/../routes/console.php', channels: __DIR__.'/../routes/channels.php', ) -withEvents(discover: [ app_path('Domain/Listeners'), ]) -create(); ``` :contentReference[oaicite:8]{index=8}

4. Check event:list whenever something feels off

   If you suspect duplicate work (emails sent twice, logs written twice, etc.), run php artisan event:list and look for repeated listeners.

5. Remember that scaling can multiply effects

   On Azure App Service or any cloud environment with multiple instances, if a listener is registered twice per instance, scaling out will amplify the problem. Fixing the duplicate registration at code level is crucial before scaling.

 

Conclusion

“Events firing multiple times” in Laravel 11 is usually not a mysterious cloud bug – it’s often a sign that the same listener has been registered more than once.

By:

• understanding how auto-discovery works,

• using a single registration strategy, and

• verifying your configuration with php artisan event:list,

you can keep your event system predictable and production-ready.

If you’re facing a similar problem in your Laravel or Azure setup, Neion Tech can help analyze your architecture and deployment pipeline to prevent these subtle bugs from slipping into production.