In today's world, web applications are expected to be available 24/7. Downtime can be costly, both in terms of revenue and user trust. To ensure your Laravel application is always up and running, it's crucial to implement health probes. In this blog post, we'll explore what health probes are, why they matter, and how to implement them effectively in your Laravel application.

Understanding Health Probes

Health probes, also known as health checks or liveness checks, are a set of tests that continuously monitor the state of your application. They provide real-time feedback on its health, enabling you to detect and address issues before they impact users. These probes typically examine key components like the database, server, and external dependencies to ensure they are functioning correctly.

Why Health Probes Matter

1. Continuous Availability: Health probes enable you to maintain high availability for your application. By regularly checking the health of your application's components, you can detect and address problems swiftly, reducing downtime.

2. Improved User Experience: Users expect your application to be available when they need it. Health probes help ensure that your application is responsive and reliable, which enhances the user experience.

3. Proactive Issue Resolution: Health probes can identify issues even before users notice them. This proactive approach to monitoring allows you to resolve problems before they escalate, reducing support requests and maintaining user trust.

4. Scalability: In a cloud-native environment, health probes are essential for auto-scaling. They help the infrastructure make informed decisions about scaling resources up or down based on the application's health.

Implementing Health Probes in Laravel

Now that we understand the importance of health probes, let's see how you can implement them in your Laravel application.

Start by creating a dedicated route for health checks in your Laravel routes file, typically routes/web.php or routes/api.php. These routes will be used by external monitoring tools to check the health of your application.

I recommend creating two routes: one for the application's health and another for the database's health.

<?php
use Illuminate\Http\JsonResponse;

Route::group(['prefix' => 'probes'], function (): void {

    // Route to check if the application is up and running
    Route::get('health', function (): JsonResponse {
        return response()->json(['status' => 'ok']);
    });

    // Route to check if the application is ready to receive requests
    Route::get('readiness', function (): JsonResponse {
        $check = DB::table('migrations')->count();
        if ($check > 0) {
            return response()->json(['status' => 'ok']);
        }
        return response()->json(['status' => 'error'], 500);
    });
});

In the readiness method, you can perform various health checks, such as verifying the database connection or checking the status of external services your application depends on. If all checks pass, return a JSON response with a status of 'ok'; otherwise, return an error response.

Finally, configure your monitoring tools to regularly make GET requests to the /probes/health and /probes/readiness endpoints. Tools like Kubernetes liveness and readiness probes or external services like Pingdom or New Relic can be used for this purpose.

Conclusion

Health probes are a crucial component of any modern web application. They provide real-time feedback on your application's health, helping you maintain high availability, improve the user experience, and proactively address issues. Implementing health probes in your Laravel application, as demonstrated in this blog post, is a step towards ensuring your application is always up and running, even in the face of unforeseen challenges.