Job retries and failure in Laravel - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of job retries in Laravel queues?

Job retries allow Laravel to automatically attempt to run a failed job again, helping to handle temporary issues like network problems or service downtime without losing the job.

beginner

How do you specify the number of times a job should be retried in Laravel?

You set the public property $tries in your job class to the number of retry attempts you want Laravel to make before marking the job as failed.

intermediate

What happens when a Laravel job fails after all retry attempts?

Laravel marks the job as failed and triggers the failed() method on the job class if defined. The job is then stored in the failed_jobs table for later review or manual retry.

intermediate

How can you handle cleanup or notifications when a job fails in Laravel?

Define a failed() method inside your job class. This method runs when the job fails after all retries, letting you send alerts or clean up resources.

beginner

What Laravel command can you use to retry all failed jobs?

Use the artisan command php artisan queue:retry all to retry every job in the failed_jobs table.

Which property controls how many times a Laravel job will be retried?

A $tries

B $timeout

C $delay

D $maxAttempts

The $tries property sets the number of retry attempts for a job.

What method can you define in a Laravel job to handle failure logic?

A onFail()

B failed()

C handleFailure()

D retry()

The failed() method runs when a job fails after all retries.

Where does Laravel store jobs that have failed after all retries?

A logs

B jobs table

C failed_jobs table

D cache

Failed jobs are stored in the failed_jobs database table.

Which artisan command retries all failed jobs in Laravel?

A php artisan queue:restart

B php artisan queue:work

C php artisan queue:flush

D php artisan queue:retry all

The command php artisan queue:retry all retries all failed jobs.

If a job fails due to a temporary network issue, what feature helps Laravel try again automatically?

A Job retries

B Job delays

C Job chaining

D Job batching

Job retries let Laravel automatically try running a job again after failure.

Explain how Laravel handles job retries and what happens when retries are exhausted.

Think about how Laravel tries again and what it does if it still fails.

Describe how you can notify your team or clean up resources when a Laravel job fails permanently.

Consider what happens after all retries fail.

Practice

1. In Laravel, what does setting the $tries property in a job class control?

easy

A. The number of times the job will be retried if it fails

B. The maximum execution time of the job

C. The priority of the job in the queue

D. The database connection used by the job

Solution

1. Step 1: Understand the role of $tries in Laravel jobs

   The $tries property defines how many times Laravel will attempt to run the job if it fails.

2. Step 2: Differentiate from other job properties

   It does not control execution time, priority, or database connection, only retry attempts.

3. Final Answer:

   The number of times the job will be retried if it fails -> Option A

4. Quick Check:

   $tries controls retry attempts [OK]

Hint: Remember: $tries means retry count for failed jobs [OK]

Common Mistakes:

• Confusing $tries with job timeout
• Thinking $tries sets job priority
• Assuming $tries controls database connection

2. Which of the following is the correct way to define a job retry limit of 5 attempts in a Laravel job class?

easy

A. public $tries = 5;

B. protected $retry = 5;

C. public $retryAttempts = 5;

D. protected $triesCount = 5;

Solution

1. Step 1: Recall the correct property name for retry attempts

   Laravel uses $tries as a public property to set retry limits.

2. Step 2: Check syntax and visibility

   The property should be public and named exactly $tries to work properly.

3. Final Answer:

   public $tries = 5; -> Option A

4. Quick Check:

   Correct property is public $tries [OK]

Hint: Use public $tries = number; to set retries [OK]

Common Mistakes:

• Using protected instead of public
• Using wrong property names like $retry or $triesCount
• Confusing retry limit with timeout

3. Given this Laravel job class snippet:

class SendEmailJob implements ShouldQueue {
    public $tries = 3;
    public function handle() {
        // code that may fail
        throw new \Exception('Failed');
    }
    public function failed() {
        // handle failure
        Log::info('Job failed permanently');
    }
}

How many times will Laravel attempt to run this job before calling failed()?

medium

A. 1 time

B. 3 times

C. 4 times

D. It will retry indefinitely

Solution

1. Step 1: Understand how $tries works

   The $tries property sets the maximum number of times the job will be attempted, including the initial attempt.

2. Step 2: Calculate total attempts

   With $tries = 3, Laravel attempts the job 3 times total before calling failed().

3. Final Answer:

   3 times -> Option B

4. Quick Check:

   Total attempts = $tries = 3 [OK]

Hint: Total attempts = $tries [OK]

Common Mistakes:

• Thinking total attempts = 1 + $tries
• Assuming retries are unlimited
• Confusing failed() call timing

4. Examine this Laravel job code:

class ProcessOrder implements ShouldQueue {
    public $tries = 2;
    public function handle() {
        // some code
        throw new \Exception('Error');
    }
    public function failed() {
        // log failure
        Log::error('Order processing failed');
    }
}

Why might the failed() method never be called after job failures?

medium

A. Because the $tries property is set to 2, so it retries infinitely

B. Because the job is not implementing the ShouldQueue interface

C. Because the job is failing but failed() is not triggered until retries are exhausted

D. Because the failed() method must accept an Exception parameter

Solution

1. Step 1: Check method signature for failed()

   Laravel expects failed() to accept an Exception parameter to receive failure details.

2. Step 2: Understand impact of missing parameter

   If failed() lacks the Exception parameter, Laravel may not call it properly after retries.

3. Final Answer:

   The failed() method must accept an Exception parameter -> Option D

4. Quick Check:

   failed(Exception $exception) required [OK]

Hint: Add Exception parameter to failed() method [OK]

Common Mistakes:

• Assuming $tries = 2 means infinite retries
• Forgetting to implement ShouldQueue interface
• Ignoring method signature requirements

5. You want a Laravel job to retry 3 times on failure, but after the last failure, you want to notify the user by email. Which is the best way to implement this behavior?

hard

A. Set public $tries = 3; and use a separate job to send the email without failed()

B. Set public $tries = 3; and send the email inside the handle() method after catching exceptions

C. Set public $tries = 3; and define a failed(Exception $exception) method to send the email notification

D. Set public $maxAttempts = 3; and send the email in the constructor

Solution

1. Step 1: Use $tries to limit retry attempts

   Setting public $tries = 3; ensures the job retries 3 times on failure.

2. Step 2: Use failed(Exception $exception) to handle final failure

   Defining failed() with the Exception parameter allows sending email after all retries fail.

3. Final Answer:

   Set public $tries = 3; and define a failed(Exception $exception) method to send the email notification -> Option C

4. Quick Check:

   Retries + failed() method for final failure handling [OK]

Hint: Use $tries and failed(Exception $exception) for retries and notification [OK]

Common Mistakes:

• Trying to send email inside handle() ignoring retries
• Using wrong property name like $maxAttempts
• Not using failed() method for final failure