AWS-Certified-DevOps-Engineer-Professional Free Practice Test

Your system uses a multi-master, multi-region DynamoDB configuration spanning two regions to achieve high availablity. For the first time since launching your system, one of the AWS Regions in which you operate over went down for 3 hours, and the failover worked correctly. However, after recovery, your users are experiencing strange bugs, in which users on different sides of the globe see different data. What is a likely design issue that was not accounted for when launching?

1. A. The system does not have Lambda Functor Repair Automations, to perform table scans and chack for corrupted partition blocks inside the Table in the recovered Region.
2. B. The system did not implement DynamoDB Table Defragmentation for restoring partition performance in the Region that experienced an outage, so data is served stale.
3. C. The system did not include repair logic and request replay buffering logic for post-failure, to re-synchronize data to the Region that was unavailable for a number of hours.
4. D. The system did not use DynamoDB Consistent Read requests, so the requests in different areas are not utilizing consensus across Regions at runtime.

Correct Answer: C
When using multi-region DynamoDB systems, it is of paramount importance to make sure that all requests made to one Region are replicated to the other. Under normal operation, the system in question would correctly perform write replays into the other Region. If a whole Region went down, the system would be unable to perform these writes for the period of downtime. Without buffering write requests somehow, there would be no way for the system to replay dropped cross-region writes, and the requests would be serviced differently depending on the Region from which they were served after recovery. Reference: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Streams.CrossRegionRepI.htmI

Your company needs to automate 3 layers of a large cloud deployment. You want to be able to track this depIoyment's evolution as it changes over time, and carefully control any alterations. What is a good way to automate a stack to meet these requirements?

1. A. Use OpsWorks Stacks with three layers to model the layering in your stack.
2. B. Use CloudFormation Nested Stack Templates, with three child stacks to represent the three logicallayers of your cloud.
3. C. Use AWS Config to declare a configuration set that AWS should roll out to your cloud.
4. D. Use Elastic Beanstalk Linked Applications, passing the important DNS entires between layers using the metadata interface.

Correct Answer: B
Only CIoudFormation allows source controlled, declarative templates as the basis for stack automation. Nested Stacks help achieve clean separation of layers while simultaneously providing a method to control all layers at once when needed.
Reference:
https://bIogs.aws.amazon.com/application-management/post/TxlT9JYOOS8AB9I/Use-Nested-Stacks-to- Create-Reusable-Templates-and-Support-Role-SpeciaIization

You are creating an application which stores extremely sensitive financial information. All information in
the system must be encrypted at rest and in transit. Which of these is a violation of this policy?

1. A. ELB SSL termination.
2. B. ELB Using Proxy Protocol v1.
3. C. CIoudFront Viewer Protocol Policy set to HTTPS redirection.
4. D. Telling S3 to use AES256 on the server-sid

Correct Answer: A
Terminating SSL terminates the security of a connection over HTTP, removing the S for "Secure" in HTTPS. This violates the "encryption in transit" requirement in the scenario.
Reference:
http://docs.aws.amazon.com/E|asticLoadBaIancing/latest/DeveIoperGuide/elb-listener-config.htmI

Which is not a restriction on AWS EBS Snapshots?

1. A. Snapshots which are shared cannot be used as a basis for other snapshots.
2. B. You cannot share a snapshot containing an AWS Access Key ID or AWS Secret Access Key.
3. C. You cannot share unencrypted snapshots.
4. D. Snapshot restorations are restricted to the region in which the snapshots are create

Correct Answer: A
Snapshots shared with other users are usable in full by the recipient, including but limited to the ability to base modified volumes and snapshots.
Reference:
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-modifying-snapshot-permissions.html