Failed job handling in Laravel - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What happens when a Laravel job fails and is retried?

Consider a Laravel queued job that throws an exception during execution. What is the default behavior of Laravel regarding this failed job?

Laravel

class ExampleJob implements ShouldQueue {
    public function handle() {
        throw new \Exception('Failing job');
    }
}

A Laravel retries the job automatically based on the retry settings before moving it to the failed_jobs table.

B Laravel immediately deletes the job from the queue and does not retry it.

C Laravel moves the job to the failed_jobs table after the first failure without retrying.

D Laravel pauses the queue worker until the job is manually deleted.

💡 Hint

Think about how Laravel handles retries and failed jobs by default.

Laravel retries failed jobs automatically according to the retry settings defined in the job or queue configuration. Only after exhausting retries does it move the job to the failed_jobs table.

📝 Syntax

intermediate

Which code snippet correctly defines a failed job handler in Laravel?

In Laravel, to handle a failed job, you can define a failed method inside your job class. Which of the following snippets correctly implements this method?

Laravel

class ProcessOrder implements ShouldQueue {
    public function handle() {
        // job logic
    }

    // failed method here
}

A

public function failed(Throwable $exception) {
    // handle failure
}

B

public function failed(string $exception) {
    // handle failure
}

C

public function failed(Error $exception) {
    // handle failure
}

D

public function failed(Exception $exception) {
    // handle failure
}

💡 Hint

Check the type hint Laravel expects for the failed method parameter.

The failed method receives a Throwable type parameter, which covers all errors and exceptions in PHP.

🔧 Debug

advanced

Why does the failed job not appear in the failed_jobs table?

A developer notices that some failed jobs are not recorded in the failed_jobs table. The queue worker is running, and jobs are failing. What is the most likely cause?

Laravel

php artisan queue:work --tries=3

// Job class does not implement ShouldQueue interface.

A The queue worker command is missing the --failed option to enable failed job logging.

B The failed_jobs table is missing from the database, so Laravel silently ignores failed jobs.

C The job class does not implement the ShouldQueue interface, so Laravel treats it as a synchronous job and does not record failures in failed_jobs.

D The job's handle method catches exceptions and prevents them from bubbling up, so Laravel never detects a failure.

💡 Hint

Think about how Laravel distinguishes queued jobs from synchronous jobs.

Only jobs implementing the ShouldQueue interface are queued and tracked by Laravel's queue system. If a job does not implement this interface, it runs synchronously and failures are not recorded in the failed_jobs table.

❓ state_output

advanced

What is the state of a job after exceeding max retries in Laravel?

A queued job has a tries property set to 2. It fails twice during execution. What is the state of this job after the second failure?

Laravel

class SendEmail implements ShouldQueue {
    public $tries = 2;

    public function handle() {
        throw new \Exception('Fail');
    }
}

A The job is retried infinitely ignoring the tries property.

B The job remains in the queue indefinitely for manual retry.

C The job is paused and the queue worker stops processing further jobs.

D The job is deleted from the queue and moved to the failed_jobs table.

💡 Hint

Consider what Laravel does when a job exceeds its retry limit.

When a job exceeds the number of allowed tries, Laravel deletes it from the queue and records it in the failed_jobs table for later inspection.

🧠 Conceptual

expert

How to programmatically retry a failed job in Laravel?

You want to retry a specific failed job stored in the failed_jobs table. Which Laravel command or method correctly retries that job?

A php artisan queue:forget {id} // retries the failed job with the given ID

B php artisan queue:retry {id} // retries the failed job with the given ID

C php artisan queue:work --retry {id} // retries the failed job with the given ID

D php artisan queue:flush {id} // retries the failed job with the given ID

💡 Hint

Look for the artisan command designed to retry failed jobs.

The queue:retry command retries failed jobs by their ID. Other commands like queue:forget remove failed jobs, and queue:flush clears all failed jobs.