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

Which of the following are not valid sources for OpsWorks custom cookbook repositories?

1. A. HTTP(S)
2. B. Git
3. C. AWS EBS
4. D. Subversion

Correct Answer: C
Linux stacks can install custom cookbooks from any of the following repository types: HTTP or Amazon S3 archives. They can be either public or private, but Amazon S3 is typically the preferred option for a private archive. Git and Subversion repositories provide source control and the ability to have multiple versions.
Reference:
http://docs.aws.amazon.com/opsworks/latest/userguide/workingcookbook-instaIlingcustom-enable.html

What is the scope of an EC2 security group?

1. A. Availability Zone
2. B. Placement Group
3. C. Region
4. D. VPC

Correct Answer: C
A security group is tied to a region and can be assigned only to instances in the same region. You can't enable an instance to communicate with an instance outside its region using security group rules. Traffic
from an instance in another region is seen as WAN bandwidth.
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/resources.htmI

What is the scope of an EBS volume?

1. A. VPC
2. B. Region
3. C. Placement Group
4. D. Availability Zone

Correct Answer: D
An Amazon EBS volume is tied to its Availability Zone and can be attached only to instances in the same Availability Zone.
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/resources.htmI

You need to create an audit log of all changes to customer banking data. You use DynamoDB to store this customer banking data. |t's important not to lose any information due to server failures. What is an elegant way to accomplish this?

1. A. Use a DynamoDB StreamSpecification and stream all changes to AWS Lambd
2. B. Log the changes toAWS CIoudWatch Logs, removing sensitive information before logging.
3. C. Before writing to DynamoDB, do a pre-write acknoledgment to disk on the application sewer, removing sensitive information before loggin
4. D. Periodically rotate these log files into S3.
5. E. Use a DynamoDB StreamSpecification and periodically flush to an EC2 instance store, removing sensitive information before putting the object
6. F. Periodically flush these batches to S3.
7. G. Before writing to DynamoDB, do a pre-write acknoledgment to disk on the application sewer, removing sensitive information before loggin
8. H. Periodically pipe these files into CloudWatch Logs.

Correct Answer: A
All suggested periodic options are sensitive to sewer failure during or between periodic flushes. Streaming to Lambda and then logging to CIoudWatch Logs will make the system resilient to instance and Availability Zone failures.
Reference: http://docs.aws.amazon.com/Iambda/latest/dg/with-ddb.html

Why are more frequent snapshots or EBS Volumes faster?

1. A. Blocks in EBS Volumes are allocated lazily, since while logically separated from other EBS Volumes, Volumes often share the same physical hardwar
2. B. Snapshotting the first time forces full block range allocation, so the second snapshot doesn't need to perform the allocation phase and is faster.
3. C. The snapshots are incremental so that only the blocks on the device that have changed after your last snapshot are saved in the new snapshot.
4. D. AWS provisions more disk throughput for burst capacity during snapshots if the drive has been pre-warmed by snapshotting and reading all blocks.
5. E. The drive is pre-warmed, so block access is more rapid for volumes when every block on the device has already been read at least one time.

Correct Answer: B
After writing data to an EBS volume, you can periodically create a snapshot of the volume to use as a baseline for new volumes or for data backup. If you make periodic snapshots of a volume, the snapshots are incremental so that only the blocks on the device that have changed after your last snapshot are saved in the new snapshot. Even though snapshots are saved incrementally, the snapshot deletion process is designed so that you need to retain only the most recent snapshot in order to restore the volume.
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-creating-snapshot.html