AWS-Certified-Solutions-Architect-Professional Free Practice Test

You are the new IT architect in a company that operates a mobile sleep tracking application.
When activated at night, the mobile app is sending collected data points of 1 kilobyte every 5 minutes to your backend.
The backend takes care of authenticating the user and writing the data points into an Amazon DynamoDB table.
Every morning, you scan the table to extract and aggregate last night's data on a per user basis, and store the results in Amazon S3. Users are notified via Amazon SNS mobile push notifications that new data is available, which is parsed and visualized by the mobile app.
Currently you have around 100k users who are mostly based out of North America. You have been tasked to optimize the architecture of the backend system to lower cost. What would you recommend? Choose 2 answers

1. A. Have the mobile app access Amazon DynamoDB directly Instead of JSON files stored on Amazon S3.
2. B. Write data directly into an Amazon Redshift cluster replacing both Amazon DynamoDB and Amazon S3.
3. C. Introduce an Amazon SQS queue to buffer writes to the Amazon DynamoDB table and reduce provisioned write throughput.
4. D. Introduce Amazon Elasticache to cache reads from the Amazon DynamoDB table and reduce provisioned read throughput.
5. E. Create a new Amazon DynamoDB table each day and drop the one for the previous day after its data is on Amazon S3.

Correct Answer: AD

Which of the following statements is correct about the number of security groups and rules applicable for an EC2-Classic instance and an EC2-VPC network interface?

1. A. In EC2-Classic, you can associate an instance with up to 5 security groups and add up to 50 rules to a security grou
2. B. In EC2-VPC, you can associate a network interface with up to 500 security groups and add up to 100 rules to a security group.
3. C. In EC2-Classic, you can associate an instance with up to 500 security groups and add up to 50 rules to a security grou
4. D. In EC2-VPC, you can associate a network interface with up to 5 security groups and add up to 100 rules to a security group.
5. E. In EC2-Classic, you can associate an instance with up to 5 security groups and add up to 100 rules to a security grou
6. F. In EC2-VPC, you can associate a network interface with up to 500 security groups and add up to 50 rules to a security group.
7. G. In EC2-Classic, you can associate an instance with up to 500 security groups and add up to 100 rules to a security grou
8. H. In EC2-VPC, you can associate a network interface with up to 5 security groups and add up to 50 rules to a security group.

Correct Answer: D
A security group acts as a virtual firewall that controls the traffic for one or more instances. When you launch an instance, you associate one or more security groups with the instance. You add rules to each security group that allow traffic to or from its associated instances. If you're using EC2-Classic, you must use security groups created specifically for EC2-Classic. In EC2-Classic, you can associate an instance with up to 500 security groups and add up to 100 rules to a security group. If you're using EC2-VPC, you must use security groups created specifically for your VPC. In EC2-VPC, you can associate a network interface with up to 5 security groups and add up to 50 rules to a security group.
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-network-security.html

What is the average queue length recommended by AWS to achieve a lower latency for the 200 PIOPS EBS volume?

1. A. 5
2. B. 1
3. C. 2
4. D. 4

Correct Answer: B
The queue length is the number of pending I/O requests for a device. The optimal average queue length will vary for every customer workload, and this value depends on a particular appIication's sensitMty to IOPS and latency. If the workload is not delivering enough I/O requests to maintain the optimal average queue length, then the EBS volume might not consistently deliver the IOPS that have been provisioned. However, if the workload maintains an average queue length that is higher than the optimal value, then the per-request I/O latency will increase; in this case, the user should provision more IOPS for his volume. AWS recommends that the user should target an optimal average queue length of 1 for every 200 provisioned IOPS and tune that value based on his application requirements.
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-workload-demand.htmI

Select the correct statement about Amazon EIastiCache.

1. A. It makes it easy to set up, manage, and scale a distributed in-memory cache environment in the cloud.
2. B. It allows you to quickly deploy your cache environment only if you install software.
3. C. It does not integrate with other Amazon Web Services.
4. D. It cannot run in the Amazon Virtual Private Cloud (Amazon VPC) environmen

Correct Answer: A
EIastiCache is a web service that makes it easy to set up, manage, and scale a distributed in-memory cache environment in the cloud. It provides a high-performance, scalable, and cost-effective caching solution, while removing the complexity associated with deploying and managing a distributed cache environment. With EIastiCache, you can quickly deploy your cache environment, without having to provision hardware or install software.
Reference: http://docs.aws.amazon.com/AmazonE|astiCache/latest/UserGuide/Whatls.html

With Amazon Elastic MapReduce (Amazon EMR) you can analyze and process vast amounts of data. The cluster is managed using an open-source framework called Hadoop.
You have set up an application to run Hadoop jobs. The application reads data from DynamoDB and generates a temporary file of 100 TBs.
The whole process runs for 30 minutes and the output of the job is stored to S3. Which of the below mentioned options is the most cost effective solution in this case?

1. A. Use Spot Instances to run Hadoop jobs and configure them with EBS volumes for persistent data storage.
2. B. Use Spot Instances to run Hadoop jobs and configure them with ephermal storage for output file storage.
3. C. Use an on demand instance to run Hadoop jobs and configure them with EBS volumes for persistent storage.
4. D. Use an on demand instance to run Hadoop jobs and configure them with ephemeral storage for output file storage.

Correct Answer: B
AWS EC2 Spot Instances allow the user to quote his own price for the EC2 computing capacity. The user can simply bid on the spare Amazon EC2 instances and run them whenever his bid exceeds the current Spot Price. The Spot Instance pricing model complements the On-Demand and Reserved Instance
pricing models, providing potentially the most cost-effective option for obtaining compute capacity, depending on the application. The only challenge with a Spot Instance is data persistence as the instance can be terminated whenever the spot price exceeds the bid price.
In the current scenario a Hadoop job is a temporary job and does not run for a longer period. It fetches data from a persistent DynamoDB. Thus, even if the instance gets terminated there will be no data loss and the job can be re-run. As the output files are large temporary files, it will be useful to store data on ephermal storage for cost savings.
Reference: http://aws.amazon.com/ec2/purchasing-options/spot-instances/