Quiz - Chapter 14 - Decoupling Workflows

Question 1

What type of subscription can SNS retry if a message fails to deliver?

Answer 1

HTTP(s)

SNS can only immediately retry sending a message to an HTTP(S) endpoint.

Question 2

Which tool can be used to sideline malformed SQS messages?

Answer 2

Dead-letter queues (DLQ)

Question 3

What type of firewall can be used in conjunction with API Gateway to help prevent DDoS attacks?

Answer 3

Web Application Firewall

Question 4

What is the maximum length of time a message may remain in an SQS queue?

Answer 4

14 Days

Question 5

Which service is SNS commonly paired with to alert users that an alarm has gone off?

Answer 5

CloudWatch

SNS and CloudWatch are commonly paired together

Question 6

If your application needs to process 5,000 messages per second, which type of SQS queue would you use?

Answer 6

SQS Standard

SQS Standard gives you a nearly unlimited number of transactions per second.

Question 7

Which layers of our applications need to be loosely coupled?

Answer 7

Internal and external

All levels of your architecture need to be loosely coupled!

Question 8

How can you ensure that your SQS messages arrive in the correct order?

Answer 8

Use an SQS FIFO queue

SQS FIFO guarantees that your messages will arrive in the correct order.

Question 9

Which tool can be used to monitor the queue depth of a DLQ?

Answer 9

CloudWatch

CloudWatch is the go-to tool for any sort of monitoring in AWS.