DOP-C01 Free Practice Test

You are planning on using the Amazon RDS facility for Fault tolerance for your application. How does Amazon RDSmuIti Availability Zone model work

1. A. A second, standby database is deployed and maintained in a different availability zone from master, using synchronous replication.
2. B. A second, standby database is deployed and maintained in a different availability zone from master using asynchronous replication.
3. C. A second, standby database is deployed and maintained in a different region from master using asynchronous replication.
4. D. A second, standby database is deployed and maintained in a different region from master using synchronous replication.

Correct Answer: A
Amazon RDS Multi-AZ deployments provide enhanced availability and durability for Database (DB)
Instances, making them a natural fit for production database
workloads. When you provision a Multi-AZ DB Instance, Amazon RDS automatically creates a primary DB Instance and synchronously replicates the data to a
standby instance in a different Availability Zone (AZ). Cach AZ runs on its own physically distinct, independent infrastructure, and is engineered to be highly reliable.
In case of an infrastructure failure, Amazon RDS performs an automatic failover to the standby (or to a read replica in the case of Amazon Aurora), so that you can
resume database operations as soon as the failover is complete.
The below diagram from the AWS documentation shows how this is configured
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Which of the following Cache Engines does Opswork have built in support for?

1. A. Redis
2. B. Memcache
3. C. Both Redis and Memcache
4. D. There is no built in support as of yet for any cache engine

Correct Answer: B
The AWS Documentation mentions
AWS OpsWorks Stacks provides built-in support for Memcached. However, if Redis better suits your requirements, you can customize your stack so that your application servers use OastiCache Redis. Although it works with Redis clusters, AWS clearly specifies that AWS Opsworks stacks provide built in support for Memcached.
Amazon OastiCache is an AWS service that makes it easy to provide caching support for your application server, using either the Memcached or Redis caching engines. OastiCache can be used to improve the application server performance running on AWS Opsworks stacks.
For more information on Opswork and Cache engines please refer to the below link:
• http://docs^ws.a mazon.com/opsworks/latest/userguide/other-se rvices-redis.htm I

You work for a startup that has developed a new photo-sharing application for mobile devices. Over recent months your application has increased in popularity; this has resulted in a decrease in the performance of the application due to the increased load. Your application has a two-tier architecture that is composed of an Auto Scaling PHP application tier and a MySQL RDS instance initially deployed with AWS CloudFormation. Your Auto Scaling group has a min value of 4 and a max value of 8. The desired capacity is now at 8 due to the high CPU utilization of the instances. After some analysis, you are confident that the performance issues stem from a constraint in CPU capacity, while memory utilization remains low. You therefore decide to move from the general-purpose M3 instances to the compute-optimized C3 instances. How would you deploy this change while minimizing any interruption to your end users?

1. A. Signin to the AWS Management Console, copy the old launch configuration, and createa new launch configuration that specifies the C3 instance
2. B. Update the AutoScaling group with the new launch configuratio
3. C. Auto Scaling will then updatethe instance type of all running instances
4. D. Signinto the AWS Management Console and update the existing launch configurationwith the newC3 instance typ
5. E. Add an UpdatePolicy attribute to your AutoScaling group that specifies an AutoScaling RollingUpdate.
6. F. Updatethe launch configuration specified in the AWS CloudFormation template with thenew C3 instance typ
7. G. Run a stack update with the new templat
8. H. Auto Scalingwill then update the instances with the new instance type.
9. I. Updatethe launch configuration specified in the AWS CloudFormation template with thenew C3 instance typ
10. J. Also add an UpdatePolicy attribute to your Auto Scalinggroup that specifies an AutoScalingRollingUpdat
11. K. Run a stack update with thenew template

Correct Answer: D
The AWS Documentation mentions the below
The AWS::AutoScaling::AutoScalingGroup resource supports an UpdatePolicy attribute. This is used to define how an Auto Scaling group resource is updated when an update to the Cloud Formation stack occurs. A common approach to updating an Auto Scaling group is to perform a rolling update, which is done by specifying the AutoScalingRollingUpdate policy. This retains the same Auto Scaling group and replaces old instances with new ones, according to the parameters specified.
For more information on Rolling Updates for Autoscaling please see the below link:
• https://aws.amazon.com/premiumsupport/knowledge-center/auto-scaling-group-rolling- updates/

Your company has an application hosted in AWS which makes use of DynamoDB. There is a requirement from the IT security department to ensure that all source IP addresses which make calls to the DynamoDB tables are recorded. Which of the following services can be used to ensure this requirement is fulfilled.

1. A. AWSCode Commit
2. B. AWSCode Pipeline
3. C. AWSCIoudTrail
4. D. AWSCIoudwatch

Correct Answer: C
The AWS Documentation mentions the following
DynamoDB is integrated with CloudTrail, a service that captures low-level API requests made by or
on behalf of DynamoDB in your AWS account and delivers the log files to an Amazon S3 bucket that you specify. CloudTrail captures calls made from the DynamoDB console or from the DynamoDB low-level API. Using the information collected by CloudTrail, you can determine what request was made to DynamoDB, the source IP address from which the request was made, who made the request, when it was made, and so on.
For more information on DynamoDB and Cloudtrail, please refer to the below link:
• http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/logging-using- cloudtrail.htmI

Your API requires the ability to stay online during AWS regional failures. Your API does not store any state, it only aggregates data from other sources - you do not have a database. What is a simple but effective way to achieve this uptime goal?

1. A. Use a CloudFront distribution to serve up your AP
2. B. Even if the region your API is in goes down, the edge locations CloudFront uses will be fine.
3. C. UseanELBand a cross-zone ELB deployment to create redundancy across datacenter
4. D. Even if a region fails, the other AZ will stay online.
5. E. Create a Route53 Weighted Round Robin record, and if one region goes down, have that region redirect to the other region.
6. F. Create a Route53 Latency Based Routing Record with Failover and point it to two identical deployments of your stateless API in two different region
7. G. Make sure both regions use Auto Scaling Groups behind ELBs.

Correct Answer: D
Failover routing lets you route traffic to a resource when the resource is healthy or to a different resource when the first resource is unhealthy. The primary and secondary resource record sets can route traffic to anything from an Amazon S3 bucket that is configured as a website to a complex tree of records.
For more information on Route53 Failover Routing, please visit the below URL:
http://docs.aws.amazon.com/Route53/latest/DeveloperGuide/routing-policy.html