Sending and receiving messages in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the primary AWS service used for sending and receiving messages between distributed components?

Amazon Simple Queue Service (SQS) is the primary AWS service used for sending, storing, and receiving messages between distributed software components or microservices.

intermediate

What is the difference between a Standard Queue and a FIFO Queue in AWS SQS?

Standard Queues offer high throughput and at-least-once delivery but may deliver messages out of order. FIFO Queues guarantee exactly-once processing and preserve the order of messages but have lower throughput.

beginner

What is a message visibility timeout in AWS SQS?

The visibility timeout is the period after a message is received during which it remains invisible to other consumers. This prevents multiple consumers from processing the same message simultaneously.

intermediate

How does AWS SQS ensure messages are not lost if a consumer fails to process them?

If a consumer fails to delete a message after processing, the message becomes visible again after the visibility timeout expires, allowing other consumers to process it.

intermediate

What AWS service can be used to trigger processing automatically when a message arrives in an SQS queue?

AWS Lambda can be configured to automatically trigger and process messages when they arrive in an SQS queue, enabling serverless message processing.

Which AWS service is designed specifically for sending and receiving messages between distributed components?

A Amazon EC2

B Amazon SQS

C Amazon RDS

D Amazon S3

Amazon SQS is the AWS service designed for message queuing between distributed components.

What does the visibility timeout in SQS prevent?

A Messages being sent to the wrong queue

B Messages being deleted too early

C Multiple consumers processing the same message simultaneously

D Messages being encrypted

Visibility timeout prevents multiple consumers from processing the same message at the same time.

Which SQS queue type guarantees the order of messages?

A FIFO Queue

B Standard Queue

C Dead-letter Queue

D Priority Queue

FIFO Queues guarantee exactly-once processing and preserve message order.

What happens to a message in SQS if the consumer fails to delete it after processing?

A It becomes visible again after the visibility timeout

B It is sent to another queue

C It is automatically archived

D It is lost permanently

If not deleted, the message becomes visible again after the visibility timeout for reprocessing.

Which AWS service can automatically process messages from an SQS queue without managing servers?

A Amazon DynamoDB

B Amazon EC2

C AWS CloudTrail

D AWS Lambda

AWS Lambda can be triggered by SQS to process messages serverlessly.

Explain how AWS SQS handles message delivery and processing to ensure reliability.

Think about how messages are hidden during processing and what happens if processing fails.

Describe the differences between Standard and FIFO queues in AWS SQS and when you might use each.

Consider speed versus order and duplication guarantees.