Question 23:
A technology blogger wants to write a review on the comparative pricing for various storage types available on AWS Cloud. The blogger has created a test file of size 1 gigabytes with some random data. Next he copies this test file into AWS S3 Standard storage class, provisions an Amazon EBS volume (General Purpose SSD (gp2)) with 100 gigabytes of provisioned storage and copies the test file into the Amazon EBS volume, and lastly copies the test file into an Amazon EFS Standard Storage filesystem.
What is the correct order of the storage charges incurred for the test file on these three storage types?
With Amazon EBS Elastic Volumes, you pay only for the resources that you use. The Amazon EFS Standard Storage pricing is $0.30 per GB per month. Therefore the cost for storing the test file on EFS is $0.30 for the month.
For Amazon EBS General Purpose SSD (gp2) volumes, the charges are $0.10 per GB-month of provisioned storage. Therefore, for a provisioned storage of 100GB for this use-case, the monthly cost on EBS is $0.10*100 = $10. This cost is irrespective of how much storage is actually consumed by the test file.
For S3 Standard storage, the pricing is $0.023 per GB per month. Therefore, the monthly storage cost on S3 for the test file is $0.023.
Question 24:
A company manages a multi-tier social media application that runs on Amazon EC2 instances behind an Application Load Balancer. The instances run in an Amazon EC2 Auto Scaling group across multiple AZs and use an Amazon Aurora database. As an AWS Certified Solutions Architect — Associate, you have been tasked to make the application more resilient to periodic spikes in request rates. Which of the following solutions would you recommend for the given use-case? (Select two)
Amazon Aurora Replicas help to increase availability. If the writer instance in a cluster becomes unavailable, Aurora automatically promotes one of the reader instances to take its place as the new writer. Up to 15 Aurora Replicas can be distributed across the AZs that a DB cluster spans within an AWS Region.
Amazon CloudFront offers an origin failover feature to help support your data resiliency needs. If your content is not already cached in an edge location, Amazon CloudFront retrieves it from an origin that you’ve identified as the source for the definitive version of the content.
Question 25:
While consolidating logs for the weekly reporting, a development team at an e-commerce company noticed that an unusually large number of illegal AWS API queries were made sometime during the week. Due to the off-season, there was no visible impact on the systems. However, this event led the management team to seek an automated solution that can trigger near-real-time warnings in case such an event recurs. Which of the following represents the best solution for the given scenario?
AWS CloudTrail log data can be ingested into Amazon CloudWatch to monitor and identify your AWS account activity against security threats, and create a governance framework for security best practices.
AWS CloudTrail integrates with the Amazon CloudWatch service to publish the API calls being made to resources or services in the AWS account. The published event has invaluable information that can be used for compliance, auditing, and governance of your AWS accounts.
Note: CloudTrail Insights helps users identify and respond to unusual activity associated with write API calls by continuously analyzing events.
Unlike other types of events captured in a CloudTrail trail, Insights events are logged only when CloudTrail detects changes in your account's API usage that differ significantly from the account's typical usage patterns.
Question 26:
A retail company has developed a REST API which is deployed in an Auto Scaling group behind an Application Load Balancer. The REST API stores the user data in Amazon DynamoDB and any static content, such as images, are served via Amazon S3. On analyzing the usage trends, it is found that 90% of the read requests are for commonly accessed data across all users. As a Solutions Architect, which of the following would you suggest as the MOST efficient solution to improve the application performance?
Amazon DynamoDB Accelerator (DAX) is tightly integrated with Amazon DynamoDB — you simply provision a DAX cluster, use the DAX client SDK to point your existing Amazon DynamoDB API calls at the DAX cluster, and let DAX handle the rest. DAX is used to natively cache Amazon DynamoDB reads.
By design, delivering data out of Amazon CloudFront can be more cost-effective than delivering it from S3 directly to your users. When a user requests content that you serve with CloudFront, their request is routed to a nearby Edge Location. If CloudFront has a cached copy of the requested file, CloudFront delivers it to the user, providing a fast (low-latency) response. If the file they’ve requested isn’t yet cached, CloudFront retrieves it from your origin — for example, the Amazon S3 bucket where you’ve stored your content. So, you can use Amazon CloudFront to improve application performance to serve static content from Amazon S3.
Incorrect options:
- Amazon ElastiCache for Redis is a great choice for real-time transactional and analytical processing use cases such as caching, chat/messaging, gaming leaderboards, geospatial, machine learning, media streaming, queues, real-time analytics, and session store.
- Amazon ElastiCache for Memcached is a great choice for implementing an in-memory cache to decrease access latency, increase throughput, and ease the load off your relational or NoSQL database. It cannot be used as a cache to serve static content from Amazon S3.
Question 27:
The product team at a startup has figured out a market need to support both stateful and stateless client-server communications via APIs developed using its platform. You have been hired by the startup as a solutions architect to build a solution to fulfill this market need using Amazon API Gateway. Which of the following would you identify as correct?
Amazon API Gateway creates RESTful APIs that:
- Are HTTP-based.
- Enable stateless client-server communication.
- Implement standard HTTP methods.
Amazon API Gateway creates WebSocket APIs that:
- Adhere to the WebSocket protocol, which enables stateful, full-duplex communication between client and server.
- Route incoming messages based on message content.
So Amazon API Gateway supports stateless RESTful APIs as well as stateful WebSocket APIs.
Question 28:
An organization wants to delegate access to a set of users from the development environment so that they can access some resources in the production environment which is managed under another AWS account. As a solutions architect, which of the following steps would you recommend?
IAM roles allow you to delegate access to users or services that normally don’t have access to your organization’s AWS resources. IAM users or AWS services can assume a role to obtain temporary security credentials that can be used to make AWS API calls. Consequently, you don’t have to share long-term credentials for access to a resource. Using IAM roles, it is possible to access cross-account resources.
Incorrect options:
- There is no need to create new IAM user credentials for the production environment, as you can use IAM roles to access cross-account resources.
- IAM roles and IAM users are separate IAM entities and should not be mixed. Only IAM roles can be used to access cross-account resources.
Question 29:
An ivy-league university is assisting NASA to find potential landing sites for exploration vehicles of unmanned missions to our neighboring planets. The university uses High Performance Computing (HPC) driven application architecture to identify these landing sites. Which of the following Amazon EC2 instance topologies should this application be deployed on?
The key thing to understand in this question is that HPC workloads need to achieve low-latency network performance necessary for tightly-coupled node-to-node communication that is typical of HPC applications. Cluster placement groups pack instances close together inside an Availability Zone. These are recommended for applications that benefit from low network latency, high network throughput, or both.
Question 30:
A leading social media analytics company is contemplating moving its dockerized application stack into AWS Cloud. The company is not sure about the pricing for using Amazon ECS with the EC2 launch type compared to ECS with the Fargate launch type. Which of the following is correct regarding the pricing for these two services?
ECS allows you to easily run, scale, and secure Docker container applications on AWS.
- With the Fargate launch type, you pay for the amount of vCPU and memory resources that your containerized application requests. vCPU and memory resources are calculated from the time your container images are pulled until the Amazon ECS Task terminates, rounded up to the nearest second.
- With the EC2 launch type, there is no additional charge for the EC2 launch type. You pay for AWS resources you create to store and run your application.
Question 31:
A gaming company uses Amazon Aurora as its primary database service. The company has now deployed 5 multi-AZ read replicas to increase the read throughput and for use as failover target. The replicas have been assigned the following failover priority tiers and corresponding instance sizes are given in parentheses: tier-1 (16 terabytes), tier-1 (32 terabytes), tier-10 (16 terabytes), tier-15 (16 terabytes), tier-15 (32 terabytes). In the event of a failover, Amazon Aurora will promote which of the following read replicas?
For Amazon Aurora, each Read Replica is associated with a priority tier (0–15). In the event of a failover, Amazon Aurora will promote the Read Replica that has the highest priority (the lowest numbered tier). If two or more Aurora Replicas share the same priority, then Amazon RDS promotes the replica that is largest in size. If two or more Aurora Replicas share the same priority and size, then Amazon Aurora promotes an arbitrary replica in the same promotion tier.
Question 32:
The engineering team at a data analytics company has observed that its flagship application functions at its peak performance when the underlying Amazon EC2 instances have a CPU utilization of about 50%. The application is built on a fleet of Amazon EC2 instances managed under an Auto Scaling group. The workflow requests are handled by an internal ALB that routes the requests to the instances. As a solutions architect, what would you recommend so that the application runs near its peak performance state?
An ASG contains a collection of EC2 instances that are treated as a logical grouping for the purposes of automatic scaling and management. An ASG also enables you to use EC2 Auto Scaling features such as health check replacements and scaling policies.
With target tracking scaling policies, you select a scaling metric and set a target value: EC2 Auto Scaling creates and manages the CloudWatch alarms that trigger the scaling policy and calculates the scaling adjustment based on the metric and the target value. The scaling policy adds or removes capacity as required to keep the metric at, or close to, the specified target value.
