Job retries and error handling in Ruby on Rails - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of job retries in Rails Active Job?

Job retries automatically try to run a failed job again after an error occurs. This helps handle temporary problems like network issues without losing the job.

beginner

How do you specify the number of retries for a job in Rails?

You use the <code>retry_on</code> method inside your job class and pass the error type and options like <code>wait</code> time and <code>attempts</code> count.

intermediate

What does the discard_on method do in a Rails job?

It tells Rails to stop retrying the job if a specific error happens. The job is discarded immediately without retrying.

intermediate

How can you customize the wait time between retries in Rails jobs?

You can pass a wait option to retry_on with a number of seconds or a block that returns the wait time. This controls how long Rails waits before retrying.

intermediate

What happens if a job keeps failing after all retries are exhausted?

The job is marked as failed and removed from the retry queue. You can handle this by defining rescue_from in the job to log or notify about the failure.

Which method in Rails Active Job is used to retry a job on specific errors?

A retry_on

B discard_on

C rescue_from

D retry_job

The retry_on method tells Rails to retry the job when certain errors happen.

What does discard_on do in a Rails job?

A Retries the job immediately

B Stops retrying and discards the job on specific errors

C Logs the error but retries anyway

D Schedules the job for later

discard_on stops retries and discards the job when the specified error occurs.

How can you set a custom wait time between retries in Rails jobs?

A Using <code>sleep</code> inside the job perform method

B Using <code>delay</code> option in <code>discard_on</code>

C Using <code>wait_for</code> method

D Using <code>wait</code> option in <code>retry_on</code>

The wait option in retry_on sets how long to wait before retrying.

If a job fails after all retries, what can you do to handle it?

A Use <code>retry_on</code> again

B Nothing, the job is lost

C Use <code>rescue_from</code> to catch and handle the failure

D Use <code>discard_on</code> to retry

rescue_from lets you handle errors after retries are exhausted.

Which of these is NOT a valid way to handle errors in Rails jobs?

A retry_job_forever

B discard_on

C rescue_from

D retry_on

retry_job_forever is not a valid Rails Active Job method.

Explain how job retries work in Rails Active Job and how you can control retry behavior.

Think about how Rails tries again after errors and how you tell it when to stop.

Describe how you would handle a job failure after all retry attempts have been used in Rails.

Consider what happens when retries run out and how to respond.