Dead-letter queue (DLQ) quiz · Level 0

Question 1One malformed message makes Todo.io's worker fail every time, so it is retried forever. How should Todo.io deal with messages like this?

Give the queue a redrive policy that moves a message to a dead-letter queue after a set number of receives (maxReceiveCount).Correct. The bad message is set aside in the DLQ for someone to inspect, fix and redrive.Raise the visibility timeout.Not this one. The message would fail just as often, only more slowly.Switch to a FIFO queue.Not this one. FIFO keeps order; it doesn't stop endless retries.Delete the queue and create a new one.Not this one. That loses every other message too.

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Question 2Todo.io's source queue is a FIFO queue. What kind of queue can be its dead-letter queue?

A FIFO queue.Correct. A DLQ must be the same type as its source queue.A standard queue.Not this one. A FIFO queue needs a FIFO DLQ.Any queue in the account.Not this one. The types must match.A CloudWatch log group.Not this one. A DLQ is always another SQS queue.

Learn it: Dead-letter queue (DLQ)

Question 3What does "Dead-letter queue (DLQ)" mean?

A side queue where messages go after failing too many times.Correct. Think of it as: The "problem orders" tray, so one bad order doesn't block the kitchen.A managed queue. One part of your system drops messages in, another takes them out later.Not this one. That describes SQS (Simple Queue Service).Records how your resources are configured over time and checks them against rules.Not this one. That describes AWS Config.A record of every AWS API call. Who did what, when, from where.Not this one. That describes CloudTrail.

Learn it: Dead-letter queue (DLQ)

Question 4Which term is this? "A side queue where messages go after failing too many times."

Dead-letter queue (DLQ)Correct. Yes. Think of it as: The "problem orders" tray, so one bad order doesn't block the kitchen.SQS (Simple Queue Service)Not this one. SQS (Simple Queue Service) is: A managed queue. One part of your system drops messages in, another takes them out later.AWS ConfigNot this one. AWS Config is: Records how your resources are configured over time and checks them against rules.CloudTrailNot this one. CloudTrail is: A record of every AWS API call. Who did what, when, from where.

Learn it: Dead-letter queue (DLQ)

Question 5Which AWS term is described by this analogy? "The "problem orders" tray, so one bad order doesn't block the kitchen."

Dead-letter queue (DLQ)Correct. Yes: A side queue where messages go after failing too many times.SQS (Simple Queue Service)Not this one. SQS (Simple Queue Service) is: A managed queue. One part of your system drops messages in, another takes them out later. Its analogy: A ticket rail in a restaurant kitchen. Waiters clip orders up, cooks take them down when ready.AWS ConfigNot this one. AWS Config is: Records how your resources are configured over time and checks them against rules. Its analogy: A building inspector with a notebook and a camera.CloudTrailNot this one. CloudTrail is: A record of every AWS API call. Who did what, when, from where. Its analogy: The building's CCTV and visitor book.

Learn it: Dead-letter queue (DLQ)

Dead-letter queue (DLQ)

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