Practice test 4

Question 1

What is AWS X-Ray ?

Answer 1

Distribute tracing going through the API Gateway.

Question 2

For EBS volumes, What is the volume queue length ?

Answer 2

Is the number of pending I/O requests for a device

Question 3

For EBS Volumes. What is latency ?

Answer 3

Latency is the true end-to-end client time of an I/O operation

Question 4

What are the advantages of a SQS FIFO Queue ?

Answer 4

FIFO

• Keeps the original order.
• Doesn’t duplicate events.

Question 5

What is Amazon SWF ?

Answer 5

Amazon Simple Workflow Service.

Question 6

Amazon Step Functions vs SWF

Answer 6

Watch video https://www.youtube.com/watch?v=D6qV3bC4rNw

Question 7

Which useful guarantees around task assignments are offered by Amazon SWF ?

Answer 7

• It ensures that a task is never duplicated.

- And that is assigned only once.

Question 8

You need at least six instances running in three AZs in one region. How do you distribute the instances among the AZs in-case one of them fails?

Answer 8

Two solutions:

a) 3, 3, and 3.
b) 6, 6, and 0.

The key is that to guarantee 6 you may need to have more (e.g. 9 or 12).

Question 9

What do you need to do to trigger AutoScale out when memory is high ?

Answer 9

You need to install the CloudWatch agent to be able to monitor high memory metric.

Question 10

What is AWS DataSync ?

Answer 10

AWS DataSync simplifies, automates, and accelerates copying large amounts of data to and from AWS storage services over the internet

Question 11

What happens when you enable Amazon S3 server access logs ?

Answer 11

Detailed records are generated for the requests that are made to an S3 bucket. They are copied to a target bucket.

Question 12

What is S3 Transfer acceleration ?

Answer 12

Enables fast, easy, and secure transfer of files over long distances between your client and your Amazon S3 bucket

Question 13

Metrics in RDS. Which are standard and which are enhanced:

Answer 13

Standard:
- CPUUtilization
-Read and Write Latency.
- Freeable Memory
Enhanced:
- A ton of OS metrics

Question 14

How to ensure that all objects uplodad to a bucket can be read publicly over the Internet ?

Answer 14

a) Configure the S3 bucket policy to set all objects to public read.
b) Grant public read access to the object when uploading it using S3 Console.

Question 15

Which of these is Servless? AWS Step Function or SWF

Answer 15

AWS Step Functions

Question 16

Where can you import SSL/TLS certificates ?

Answer 16

• IAM Certificate Store
• AWS Certificate Manager.

You could load certificates in CloudFront but you would not be able to share them with the ELB.

Question 17

How to configure RDS (mysql) for Active-Passive failover.

Answer 17

Create a stand by replica in another availability zone by enabling Multi-AZ deployment.

Question 18

Should you choose a Provisioned IOPS SSD if you only need ephemeral storage ?

Answer 18

No