Managing Long Running Tasks medium
In SQS, what is the 'Visibility Timeout'?
- A How long a user can look at the screen.
- B The time until the message is deleted.
- C A CSS property.
- D The duration a message becomes 'invisible' to other workers after one worker picks it up. If the worker doesn't delete it within this time (e.g., crashes), the message reappears for others to retry.
Answer: D. The duration a message becomes 'invisible' to other workers after one worker picks it up. If the worker doesn't delete it within this time (e.g., crashes), the message reappears for others to retry.
Crucial mechanism for handling worker failures without losing messages.
One system design question a day, with spaced repetition so the ones you miss come back.
Get the appRelated questions
- What is the primary purpose of a Dead Letter Queue (DLQ)?
- The architectural pattern where one service creates tasks and another processes them is called:
- In a Priority Queue system (High vs Low), what is 'Starvation' and how do you fix it?
- How do you atomically update your local database AND publish a message to a queue without losing sync if the process crashes in between?
- What does 'Fire and Forget' mean?
- Why might you 'Throttle' (limit the speed of) your background workers?