A Solutions Architect is working for a large IT consulting firm. One of the clients is launching a file sharing web application in AWS which requires a durable storage service for hosting their static contents such as PDFs, Word Documents, high-resolution images, and many others.
Which type of storage service should the Architect use to meet this requirement?

• A.Amazon EBS volume
• B.Amazon S3
• C.Amazon EC2 instance store
• D.Amazon RDS instance

Correct Answer: B

Amazon S3 is storage for the Internet. It's a simple storage service that offers software developers a durable, highly-scalable, reliable, and low-latency data storage infrastructure at very low costs. Amazon S3 provides customers with a highly durable storage infrastructure. Versioning offers an additional level of protection by providing a means of recovery when customers accidentally overwrite or delete objects.
Remember that the scenario requires a durable storage for static content. These two keywords are actually referring to S3, since it is highly durable and suitable for storing static content. Hence, Amazon S3 is the correct answer.


Amazon EBS volume is incorrect because this is not as durable compared with S3. In addition, it is best to store the static contents in S3 rather than EBS.
Amazon EC2 instance store is incorrect because it is definitely not suitable - the data it holds will be wiped out immediately once the EC2 instance is restarted.
Amazon RDS instance is incorrect because an RDS instance is just a database and not suitable for storing static content. By default, RDS is not durable, unless you launch it to be in Multi-AZ deployments configuration.
Explanation:
Reference:
https://aws.amazon.com/s3/faqs/
https://d1.awsstatic.com/whitepapers/Storage/AWS%20Storage%20Services%20Whitepaper-v9.pdf#pa ge=24 Check out this Amazon S3 Cheat Sheet:
https://tutorialsdojo.com/amazon-s3/

Comment: *

Name: *

Email: *

Verification: *

An application consists of multiple EC2 instances in private subnets in different availability zones.
The application uses a single NAT Gateway for downloading software patches from the Internet to the instances. There is a requirement to protect the application from a single point of failure when the NAT Gateway encounters a failure or if its availability zone goes down.
How should the Solutions Architect redesign the architecture to be more highly available and cost- effective

• A.Create two NAT Gateways in each availability zone. Configure the route table in each public subnet to ensure that instances use the NAT Gateway in the same availability zone.
• B.Create a NAT Gateway in each availability zone. Configure the route table in each public subnet to ensure that instances use the NAT Gateway in the same availability zone.
• C.Create three NAT Gateways in each availability zone. Configure the route table in each private subnet to ensure that instances use the NAT Gateway in the same availability zone.
• D.Create a NAT Gateway in each availability zone. Configure the route table in each private subnet to ensure that instances use the NAT Gateway in the same availability zone

Correct Answer: D

A NAT Gateway is a highly available, managed Network Address Translation (NAT) service for your resources in a private subnet to access the Internet. NAT gateway is created in a specific Availability Zone and implemented with redundancy in that zone.
You must create a NAT gateway on a public subnet to enable instances in a private subnet to connect to the Internet or other AWS services, but prevent the Internet from initiating a connection with those instances.

If you have resources in multiple Availability Zones and they share one NAT gateway, and if the NAT gateway's Availability Zone is down, resources in the other Availability Zones lose Internet access. To create an Availability Zone-independent architecture, create a NAT gateway in each Availability Zone and configure your routing to ensure that resources use the NAT gateway in the same Availability Zone.
Hence, the correct answer is: Create a NAT Gateway in each availability zone. Configure the route table in each private subnet to ensure that instances use the NAT Gateway in the same availability zone. The option that says: Create a NAT Gateway in each availability zone. Configure the route table in each public subnet to ensure that instances use the NAT Gateway in the same availability zone is incorrect because you should configure the route table in the private subnet and not the public subnet to associate the right instances in the private subnet.
The options that say: Create two NAT Gateways in each availability zone. Configure the route table in each public subnet to ensure that instances use the NAT Gateway in the same availability zone and Create three NAT Gateways in each availability zone. Configure the route table in each private subnet to ensure that instances use the NAT Gateway in the same availability zone are both incorrect because a single NAT Gateway in each availability zone is enough. NAT Gateway is already redundant in nature, meaning, AWS already handles any failures that occur in your NAT Gateway in an availability zone.
References:
https://docs.aws.amazon.com/vpc/latest/userguide/vpc-nat-gateway.html
https://docs.aws.amazon.com/vpc/latest/userguide/vpc-nat-comparison.html Check out this Amazon VPC Cheat Sheet:
https://tutorialsdojo.com/amazon-vpc/

Comment: *

Name: *

Email: *

Verification: *

An Auto Scaling group (ASG) of Linux EC2 instances has an Amazon FSx for OpenZFS file system with basic monitoring enabled in CloudWatch. The Solutions Architect noticed that the legacy web application hosted in the ASG takes a long time to load. After checking the instances, the Architect noticed that the ASG is not launching more instances as it should be, even though the servers already have high memory usage.
Which of the following options should the Architect implement to solve this issue?

• A.Implement an AI solution that leverages Amazon Comprehend to track the near-real-time memory usage of each and every EC2 instance? Use Amazon SageMaker to automatically trigger the Auto Scaling event if there is high memory usage.
• B.Install the CloudWatch unified agent to the EC2 instances. Set up a custom parameter in AWS Systems Manager Parameter Store with the CloudWatch agent configuration to create an aggregated metric on memory usage percentage. Scale the Auto Scaling group based on the aggregated metric.
• C.Set up Amazon Rekognition to automatically identify and recognize the cause of the high memory usage. Use the AWS Well-Architected Tool to automatically trigger the scale-out event in the ASG based on the overall memory usage.
• D.Enable detailed monitoring on the Amazon EC2 instances of the Auto Scaling group. Use Amazon Forecast to automatically scale out the Auto Scaling group based on the aggregated memory usage of Amazon EC2 instances.

Correct Answer: B

Amazon CloudWatch agent enables you to collect both system metrics and log files from Amazon EC2 instances and on-premises servers. The agent supports both Windows Server and Linux and allows you to select the metrics to be collected, including sub-resource metrics such as per-CPU core.


The premise of the scenario is that the EC2 servers have high memory usage, but since this specific metric is not tracked by the Auto Scaling group by default, the scaling out activity is not being triggered.
Remember that by default, CloudWatch doesn't monitor memory usage but only the CPU utilization, Network utilization, Disk performance, and Disk Reads/Writes.
This is the reason why you have to install a CloudWatch agent in your EC2 instances to collect and monitor the custom metric (memory usage), which will be used by your Auto Scaling Group as a trigger for scaling activities.
The AWS Systems Manager Parameter Store is one of the capabilities of AWS Systems Manager. It provides secure, hierarchical storage for configuration data management and secrets management. You can store data such as passwords, database strings, Amazon Machine Image (AMI) IDs, and license codes as parameter values. You can store values as plain text or encrypted data. You can reference Systems Manager parameters in your scripts, commands, SSM documents, and configuration and automation workflows by using the unique name that you specified when you created the parameter.
Hence, the correct answer is: Install the CloudWatch unified agent to the EC2 instances. Set up a custom parameter in AWS Systems Manager Parameter Store with the CloudWatch agent configuration to create an aggregated metric on memory usage percentage. Scale the Auto Scaling group based on the aggregated metric The option that says: Implement an AI solution that leverages Amazon Comprehend to track the near- real-time memory usage of each and every EC2 instance? Use Amazon SageMaker to automatically trigger the Auto Scaling event if there is high memory usage is incorrect because Amazon Comprehend cannot track near-real-time memory usage in Amazon EC2. This is just a natural-language processing (NLP) service that uses machine learning to uncover valuable insights and connections in text. Also, the use of an Amazon SageMaker in this scenario is not warranted since there is no machine learning requirement involved.
The option that says: Enable detailed monitoring on the Amazon EC2 instances of the Auto Scaling group. Use Amazon Forecast to automatically scale out the Auto Scaling group based on the aggregated memory usage of Amazon EC2 instances is incorrect because detailed monitoring does not provide metrics for memory usage. CloudWatch does not monitor memory usage in its default set of EC2 metrics and detailed monitoring just provides a higher frequency of metrics (1-minute frequency). Amazon Forecast is a time-series forecasting service based on machine learning (ML) and built for business metrics analysis - not for scaling out an Auto Scaling group based on an aggregated metfic.
The option that says: Set up Amazon Rekognition to automatically identify and recognize the cause of the high memory usage. Use the AWS Well-Architected Tool to automatically trigger the scale-out event in the ASG based on the overall memory usage is incorrect because Amazon Rekognition is simply an image recognition service that detects objects, scenes, and faces; extracts text; recognizes celebrities; and identifies inappropriate content in images. It can't be used to track the high memory usage of your Amazon EC2 instances. The AWS Well-Architected Tool, on the other hand, is designed to help you review the state of your applications and workloads. It merely provides a central place for architectural best practices in AWS and nothing more.
References:
https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Install-CloudWatch-Agent.html
https://aws.amazon.com/blogs/mt/create-amazon-ec2-auto-scaling-policy-memory-utilization-metric-linux
/
https://docs.aws.amazon.com/systems-manager/latest/userguide/systems-manager-parameter-store.htm l Check out these Amazon EC2 and CloudWatch Cheat Sheets: https://tutorialsdojo.com/amazon-elastic- compute-cloud-amazon-ec2/ https://tutorialsdojo.com/amazon-cloudwatch/

Comment: *

Name: *

Email: *

Verification: *

An application is hosted in an On-Demand EC2 instance and is using Amazon SDK to communicate to other AWS services such as S3, DynamoDB, and many others. As part of the upcoming IT audit, you need to ensure that all API calls to your AWS resources are logged and durably stored.
Which is the most suitable service that you should use to meet this requirement?

• A.AWS X-Ray
• B.Amazon CloudWatch
• C.Amazon API Gateway
• D.AWS CloudTrail

Comment: *

Name: *

Email: *

Verification: *

An application is hosted in an Auto Scaling group of EC2 instances. To improve the monitoring process, you have to configure the current capacity to increase or decrease based on a set of scaling adjustments. This should be done by specifying the scaling metrics and threshold values for the CloudWatch alarms that trigger the scaling process.
Which of the following is the most suitable type of scaling policy that you should use?

• A.Target tracking scaling
• B.Scheduled Scaling
• C.Simple scaling
• D.Step scaling

Correct Answer: D

With step scaling, you choose scaling metrics and threshold values for the CloudWatch alarms that trigger the scaling process as well as define how your scalable target should be scaled when a threshold is in breach for a specified number of evaluation periods. Step scaling policies increase or decrease the current capacity of a scalable target based on a set of scaling adjustments, known as step adjustments.
The adjustments vary based on the size of the alarm breach. After a scaling activity is started, the policy continues to respond to additional alarms, even while a scaling activity is in progress. Therefore, all alarms that are breached are evaluated by Application Auto Scaling as it receives the alarm messages.
When you configure dynamic scaling, you must define how to scale in response to changing demand.
For example, you have a web application that currently runs on two instances and you want the CPU utilization of the Auto Scaling group to stay at around 50 percent when the load on the application changes. This gives you extra capacity to handle traffic spikes without maintaining an excessive amount of idle resources. You can configure your Auto Scaling group to scale automatically to meet this need.
The policy type determines how the scaling action is performed.

Amazon EC2 Auto Scaling supports the following types of scaling policies:
Target tracking scaling - Increase or decrease the current capacity of the group based on a target value for a specific metric. This is similar to the way that your thermostat maintains the temperature of your home - you select a temperature and the thermostat does the rest.
Step scaling - Increase or decrease the current capacity of the group based on a set of scaling adjustments, known as step adjustments, that vary based on the size of the alarm breach. Simple scaling - Increase or decrease the current capacity of the group based on a single scaling adjustment.
If you are scaling based on a utilization metric that increases or decreases proportionally to the number of instances in an Auto Scaling group, then it is recommended that you use target tracking scaling policies. Otherwise, it is better to use step scaling policies instead. Hence, the correct answer in this scenario is Step Scaling.
Target tracking scaling is incorrect because the target tracking scaling policy increases or decreases the current capacity of the group based on a target value for a specific metric, instead of a set of scaling adjustments.
Simple scaling is incorrect because the simple scaling policy increases or decreases the current capacity of the group based on a single scaling adjustment, instead of a set of scaling adjustments.
Scheduled Scaling is incorrect because the scheduled scaling policy is based on a schedule that allows you to set your own scaling schedule for predictable load changes. This is not considered as one of the types of dynamic scaling.
References:
https://docs.aws.amazon.com/autoscaling/ec2/userguide/as-scale-based-on-demand.html
https://docs.aws.amazon.com/autoscaling/application/userguide/application-auto-scaling-step-scaling-pol icies.html

Comment: *

Name: *

Email: *

Verification: *