SOA-C02 Reliability and Business Continuity Practice Test 12 — 15 Questions

Question 1

A company uses AWS CloudFormation to deploy its infrastructure. The SysOps administrator needs to ensure that the application stack can be recreated in another AWS Region in the event of a disaster. The stack includes an RDS MySQL database and an EC2 instance running a web server. The administrator wants to automate the backup of the RDS database and the EC2 instance configuration. What is the MOST efficient way to achieve this?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Use AWS Backup to create backup plans that include the RDS instance and EC2 instance, and copy backups to the secondary region.. AWS Backup provides a centralized, automated way to create backup plans that include both RDS and EC2 instances, and it supports cross-region backup copies. This meets the requirement to automate backups and ensure they are available in a secondary region for disaster recovery. It is the most efficient because it eliminates manual scripting and snapshot management.

Answer

Use S3 to store database dump files and instance configuration scripts.

Answer

Create manual snapshots of the RDS database and EC2 instance every day and copy them to the secondary region.

Answer

Store the CloudFormation template in S3 and use it to recreate the stack in the secondary region.

Question 2

A company runs a production application on EC2 instances in an Auto Scaling group behind an Application Load Balancer. The application uses an RDS for PostgreSQL database. The SysOps administrator has configured a read replica in a different AWS Region for disaster recovery. During a disaster, the primary region becomes unavailable. The administrator promotes the read replica to a standalone instance. After promoting, the application fails to connect to the new database because the endpoint changed. The administrator needs to minimize downtime. What should the administrator do to handle the endpoint change automatically?

Accepted Answer

Use Amazon Route 53 with a weighted alias record that points to the primary database endpoint, and configure a health check to fail over to the secondary endpoint.. By using Amazon Route 53 with a weighted alias record that points to the primary database endpoint and configuring a health check, the administrator can automate DNS failover. When the primary region becomes unavailable, the health check fails, and Route 53 automatically routes traffic to the secondary record that points to the promoted read replica's endpoint. This minimizes downtime. Option A is wrong because Elastic IP addresses cannot be assigned to RDS instances; they are used for EC2 instances. Option C is wrong because manually updating application configuration files would increase downtime and is not automatic. Option D is wrong because an RDS proxy does not automatically update the endpoint after a disaster recovery promotion; it still requires the endpoint to be changed in the application configuration.

Answer

Assign an Elastic IP address to the RDS instance.

Answer

Update the application configuration files to point to the new endpoint.

Answer

Use an RDS proxy and configure it to automatically failover to the promoted replica.

Question 3

A company runs a critical web application on EC2 instances behind an Application Load Balancer (ALB) across three Availability Zones. The application stores session data in memory on the EC2 instances. During a deployment, a new version of the application is released by terminating and replacing instances. Users report that they are unexpectedly logged out during the deployment. What should a SysOps administrator do to improve the reliability of the application during deployments?

Accepted Answer

Use an ElastiCache cluster to store session state externally.. Storing session state externally in an ElastiCache cluster decouples session data from individual EC2 instances. When instances are terminated and replaced during deployment, the new instances can retrieve session state from the shared ElastiCache cluster, preventing users from being logged out. This approach ensures that session data persists independently of the EC2 instance lifecycle, maintaining application reliability during rolling updates.

Answer

Reduce the deployment to a single Availability Zone to minimize instance churn.

Answer

Store session data in an RDS Multi-AZ database.

Answer

Enable sticky sessions (session affinity) on the ALB.

Question 4

A company uses AWS CloudFormation to deploy a multi-tier application. The stack includes an RDS DB instance with automated backups enabled. The SysOps administrator needs to ensure that the database can be recovered to any point within the last 35 days with minimal data loss. What should the administrator do?

Accepted Answer

Set the backup retention period to 35 days.. Automated backups in RDS allow point-in-time recovery (PITR) to any second within the backup retention period. By setting the retention period to 35 days, the administrator enables recovery to any point within that window, minimizing data loss to the last committed transaction before the restore time.

Answer

Create a manual snapshot daily and retain 35 snapshots.

Answer

Enable Multi-AZ on the RDS instance.

Answer

Configure AWS Backup with a 35-day backup plan.

Question 5

A company runs a production workload on a fleet of EC2 instances in an Auto Scaling group (ASG). The ASG spans three Availability Zones. To avoid regional failure, the company wants to replicate the infrastructure in a second AWS Region and be able to fail over within 30 minutes. The application state is stored in an RDS MySQL database. What is the MOST cost-effective and reliable solution?

Accepted Answer

Create a cross-Region read replica of the RDS database. In the secondary Region, deploy a duplicate ASG and ALB. In a disaster, promote the read replica to a standalone instance and update Route 53 DNS.. It provides a cost-effective and reliable disaster recovery solution that meets the 30-minute failover requirement. A cross-Region read replica of RDS MySQL allows you to maintain an up-to-date copy of the database in the secondary Region with minimal cost (only paying for the replica instance and data transfer). In a disaster, you can promote the read replica to a standalone instance in minutes, and with a pre-deployed ASG and ALG in the secondary Region, you can update Route 53 DNS to redirect traffic, achieving failover within the required timeframe.

Answer

Use an Application Load Balancer with cross-Region load balancing to distribute traffic to both Regions.

Answer

Use RDS Multi-AZ in both Regions and configure synchronous replication between them.

Answer

Take daily snapshots of the RDS database and copy them to the secondary Region. In the event of a failure, restore the latest snapshot.

Question 6

A SysOps administrator receives an alert that an EC2 instance in an Auto Scaling group is unhealthy. The instance fails the EC2 status check. What is the BEST course of action to restore availability automatically?

Accepted Answer

Configure the Auto Scaling group to use EC2 status checks for health checks and set the health check grace period appropriately.. Configuring the Auto Scaling group to use EC2 status checks for health checks allows it to automatically detect when an instance fails the EC2 status check and replace it with a new one, ensuring high availability without manual intervention. The health check grace period prevents premature termination during initial instance bootstrapping. This is the most automated and resilient approach for restoring availability in response to EC2 status check failures.

Answer

Use AWS Systems Manager to replace the underlying host.

Answer

Manually reboot the instance from the EC2 console.

Answer

Create a CloudWatch alarm that triggers an SNS notification to the administrator.

Question 7

A company runs a web application on EC2 instances in an Auto Scaling group. The application is behind an Application Load Balancer. The company wants to ensure that the application can handle a sudden spike in traffic without downtime. What should the SysOps administrator do?

Accepted Answer

Configure a target tracking scaling policy based on average CPU utilization.. A target tracking scaling policy based on average CPU utilization allows the Auto Scaling group to automatically adjust capacity in response to real-time demand spikes. This dynamic scaling approach maintains a target metric (e.g., 50% CPU) by adding or removing instances, ensuring the application can handle sudden traffic bursts without downtime.

Answer

Use a scheduled scaling policy to add instances during business hours.

Answer

Reduce the number of Availability Zones to lower latency.

Answer

Manually increase the desired capacity of the Auto Scaling group when traffic increases.

Question 8

A company has a production RDS for MySQL database. The SysOps administrator receives an alert that the database instance is running out of storage. The company requires high availability and minimal downtime during any modifications. What should the administrator do?

Accepted Answer

Modify the RDS instance to increase the allocated storage. Since the instance is Multi-AZ, the modification will be applied with minimal downtime.. Modifying the allocated storage on a Multi-AZ RDS for MySQL instance can be done with minimal downtime. When you modify storage settings, Amazon RDS performs the update in the background, and for Multi-AZ deployments, the modification is applied to the standby first, then a failover occurs to minimize any interruption. This approach satisfies the high availability requirement and keeps downtime to a few seconds or less.

Answer

Add a read replica and use it for read traffic to reduce load on the primary.

Answer

Create a CloudWatch alarm to notify when storage is low, then manually clean up old data.

Answer

Create a new RDS instance with larger storage and migrate the data using AWS Database Migration Service.

Question 9

A company runs a stateless web application on EC2 instances in an Auto Scaling group. The application is deployed across multiple Availability Zones. The SysOps administrator wants to ensure that the application remains available even if an entire Availability Zone fails. What is the MOST effective way to achieve this?

Accepted Answer

Configure the Auto Scaling group to launch instances in at least two Availability Zones.. By configuring the Auto Scaling group to launch instances in at least two Availability Zones, the application can survive the failure of an entire AZ because the Auto Scaling group will automatically replace failed instances in the remaining healthy AZs. This design ensures that the stateless web application remains available as long as at least one AZ is operational, leveraging the fault isolation that AWS Availability Zones provide. The Auto Scaling group distributes instances across the specified AZs and will maintain the desired capacity even if one AZ becomes completely unavailable.

Answer

Create a CloudWatch alarm to reboot instances when they become unhealthy.

Answer

Use a single Availability Zone to reduce complexity.

Answer

Use a larger instance type to handle more traffic.

Question 10

A company runs a critical application on AWS Lambda functions. The functions are invoked by an API Gateway endpoint. The SysOps administrator needs to ensure that the application continues to work if an entire AWS Region becomes unavailable. What should the administrator do?

Accepted Answer

Deploy the same API Gateway and Lambda setup in a second Region and use Route 53 with failover routing.. Deploying the same API Gateway and Lambda setup in a second AWS Region and using Route 53 with failover routing creates an active-passive disaster recovery architecture. Route 53 health checks monitor the primary Region's endpoint, and if it becomes unhealthy (e.g., due to a regional outage), DNS failover automatically routes traffic to the secondary Region, ensuring continuous operation of the application.

Answer

Use AWS Global Accelerator to route traffic to the closest Region.

Answer

Configure Lambda functions with provisioned concurrency in multiple Regions.

Answer

Use Lambda@Edge to run the functions at edge locations.

Question 11

A company runs a web application on EC2 instances in an Auto Scaling group behind an ALB. The application uses an RDS MySQL database. The SysOps administrator needs to improve the reliability of the database layer. Which TWO actions should the administrator take? (Choose two.)

Accepted Answer

Enable Multi-AZ on the RDS instance.. Enabling Multi-AZ on an RDS MySQL instance automatically provisions and maintains a synchronous standby replica in a different Availability Zone. If the primary instance fails, Amazon RDS automatically fails over to the standby, providing high availability and improving database reliability without manual intervention. This directly addresses the need for a resilient database layer.

Answer

Take a manual snapshot every hour.

Answer

Create a read replica in a different Region.

Answer

Increase the DB instance class to the largest available.

Question 12

A company uses AWS CloudFormation to deploy infrastructure. The SysOps administrator needs to ensure that if a stack update fails, the stack is automatically rolled back to the last known good state. Which TWO steps should the administrator take? (Choose two.)

Accepted Answer

Configure the stack to use a service role with permissions to perform rollback actions.. A service role grants CloudFormation the necessary IAM permissions to perform rollback actions on resources, such as deleting or reverting changes, even if the user who initiated the update lacks those permissions. This ensures that the stack can automatically return to its last known good state without manual intervention. Option C is correct because rollback triggers allow monitoring CloudWatch metrics; if a metric breaches the specified threshold, CloudFormation automatically rolls back the stack, providing an additional safeguard. Option E is incorrect because a stack policy only prevents updates to protected resources but does not enable or automate rollback on failure.

Answer

Create a manual snapshot of the database before each update.

Answer

Enable termination protection on the stack.

Answer

Define a stack policy that prevents updates to the database resources.

Question 13

A company runs a critical application on EC2 instances in an Auto Scaling group. The group uses a dynamic scaling policy based on CPU utilization. The SysOps administrator wants to ensure that the application remains available during a planned maintenance event that will take down one of the Availability Zones. Which TWO actions should the administrator take? (Choose two.)

Accepted Answer

Update the Auto Scaling group to remove the affected Availability Zone from the list of enabled AZs.. Removing the affected Availability Zone from the Auto Scaling group prevents the group from launching new instances in a zone that will become unavailable during maintenance. This ensures that any new instances are launched only in the remaining healthy Availability Zones, maintaining application availability. Option C is correct because increasing the desired capacity temporarily compensates for the instances that will be terminated or become unreachable in the affected zone, ensuring the group has enough running instances to handle the load.

Answer

Manually terminate all instances in the affected Availability Zone.

Answer

Create a new launch configuration with a different AMI.

Answer

Disable the dynamic scaling policy to prevent scaling.

Question 14

A SysOps administrator is configuring an Amazon RDS for MySQL Multi-AZ deployment. What is the primary benefit of using Multi-AZ?

Accepted Answer

Automatic failover to a standby instance in a different Availability Zone.. In Amazon RDS for MySQL Multi-AZ deployments, the primary benefit is automatic failover to a standby instance in a different Availability Zone. This is achieved through synchronous replication to a standby in a separate AZ, ensuring that if the primary instance fails, RDS automatically promotes the standby to become the new primary, minimizing downtime and maintaining data durability.

Answer

Improved read performance by distributing queries across multiple instances.

Answer

Synchronous replication across AWS Regions.

Answer

Automatic creation of read replicas for disaster recovery.

Question 15

A company uses Amazon S3 to store critical data. The SysOps administrator needs to protect against accidental deletion of objects. Which combination of actions should the administrator take? (Choose the best answer.)

Accepted Answer

Enable S3 Versioning and MFA Delete on the bucket.. Enabling S3 Versioning preserves all versions of an object, allowing recovery from accidental deletion or overwrite. MFA Delete adds an additional authentication layer, requiring multi-factor authentication to permanently delete object versions or suspend versioning, thus preventing unauthorized or accidental deletions.

Answer

Apply a bucket policy that denies s3:DeleteObject for all principals.

Answer

Set a lifecycle policy to expire objects after 30 days.

Answer

Configure cross-Region replication to a different bucket.