Free DVA-C01 Exam Dumps

Question 21

Company B provides an online image recognition service and utilizes SOS to decouple system components for scalability The SQS consumers poll the imaging queue as often as possible to keep
end-to-end throughput as high as possible. However, Company B is realizing that polling in tight loops is burning CPU cycles and increasing costs with empty responses.
How can Company B reduce the number of empty responses?

A. Set the imaging queue visibility Timeout attribute to 20 seconds
B. Set the Imaging queue ReceiveMessageWaitTimeSeconds attribute to 20 seconds
C. Set the imaging queue MessageRetentionPeriod attribute to 20 seconds
D. Set the DeIaySeconds parameter of a message to 20 seconds

Correct Answer:B

Question 22

How do you configure SQS to support longer message retention?

A. Set the lVIessageRetentionPeriod attribute using the SetQueueAttributes method
B. Using a Lambda function
C. You can'
D. It is set to 14 days and cannot be changed
E. You need to request it from AWS

Correct Answer:A
To configure the message retention period, set the lVIessageRetentionPeriod attribute using the SetQueueAttributes method. This attribute is used to specify the number of seconds a message will be retained by SQS. Currently the default value for the message retention period is 4 days. Using the lVIessageRetentionPeriod attribute, the message retention period can be set anywhere from 60 seconds (1 minute), up to 1209600 seconds (14 days).
Reference: https://aws.amazon.com/sqs/faqs/

Question 23

You have been doing a lot of testing of your VPC Network by deliberately failing EC2 instances to test whether instances are failing over properly. Your customer who will be paying the AWS bill for all this asks you if he being charged for all these instances. You try to explain to him how the billing works on EC2 instances to the best of your knowledge. What would be an appropriate response to give to the customer
in regards to this?

A. Billing commences when Amazon EC2 AMI instance is completely up and billing ends as soon as the instance starts to shutdown.
B. Billing commences when Amazon EC2 initiates the boot sequence of an AMI instance and billing ends when the instance shuts down.
C. Billing only commences only after 1 hour of uptime and billing ends when the instance terminates.
D. Billing commences when Amazon EC2 initiates the boot sequence of an AMI instance and billing ends as soon as the instance starts to shutdown.

Correct Answer:B
Billing commences when Amazon EC2 initiates the boot sequence of an AMI instance. Billing ends when the instance shuts down, which could occur through a web services command, by running "shutdown -h", or through instance failure.
Reference: http://aws.amazon.com/ec2/faqs/#BiIIing

Question 24

An EC2 instance has one additional EBS volume attached to it. How can a user attach the same volume to another running instance in the same AZ?

A. Terminate the first instance and only then attach to the new instance
B. Attach the volume as read only to the second instance
C. Detach the volume first and attach to new instance
D. No need to detac
E. Just select the volume and attach it to the new instance, it will take care of mapping internally

Correct Answer:C
If an EBS volume is attached to a running EC2 instance, the user needs to detach the volume from the original instance and then attach it to a new running instance. The user doesn't need to stop / terminate the original instance.
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-detaching-volume.html

Question 25

A user is using an EBS backed instance. Which of the below mentioned statements is true?

A. The user will be charged for volume and instance only when the instance is running
B. The user will be charged for the volume even if the instance is stopped
C. The user will be charged only for the instance running cost
D. The user will not be charged for the volume if the instance is stopped

Correct Answer:B
If a user has launched an EBS backed instance, the user will be charged for the EBS volume even though the instance is in a stopped state. The instance will be charged for the EC2 hourly cost only when it is running.
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-detaching-volume.html