SOA-C02 Reliability and Business Continuity Practice Test 9 — 15 Questions

Question 1

A company runs a stateless web application on EC2 instances in an Auto Scaling group across multiple Availability Zones. The application experiences increased latency during peak hours. The SysOps administrator needs to improve the application's performance and reliability. Which action should be taken?

Accepted Answer

Increase the maximum instance count in the Auto Scaling group.. Option D is correct because adding more instances via a higher max size allows the ASG to scale out to handle increased load, improving performance and reliability. Option A is wrong because changing the scaling metric to memory utilization may not reflect the actual load. Option B is wrong because switching to a larger instance type is less elastic than scaling out. Option C is wrong because reducing the cooldown period could cause thrashing.

Answer

Use larger EC2 instance types instead of smaller ones.

Answer

Reduce the Auto Scaling group's cooldown period to scale out faster.

Answer

Change the scaling metric from CPU utilization to memory utilization.

Question 2

A company has a production RDS for PostgreSQL instance with Multi-AZ enabled. During a recent failover test, the application experienced a 5-minute downtime. The company requires that failover be completed within 2 minutes. Which action should be taken to meet this requirement?

Accepted Answer

Configure an RDS Proxy in front of the database.. Option C is correct because RDS Proxy reduces failover time by pooling database connections and maintaining them during failover. Option A is wrong because increasing instance size does not directly reduce failover time. Option B is wrong because enabling automatic backups does not affect failover speed. Option D is wrong because switching to Aurora may help but is a larger architectural change; RDS Proxy is a simpler solution for RDS.

Answer

Migrate the database to Amazon Aurora with Multi-AZ.

Answer

Enable automated backups with a short retention period.

Answer

Increase the DB instance class to a larger size.

Question 3

A company uses Amazon Route 53 for DNS resolution. The company wants to ensure that if a web server becomes unhealthy, traffic is automatically routed to a healthy server in another Availability Zone. Which routing policy should be used?

Accepted Answer

Failover routing policy. Option A is correct because failover routing policy directs traffic to a primary resource, and if it is unhealthy, to a secondary resource. Option B is wrong because weighted routing distributes traffic proportionally, not based on health. Option C is wrong because latency routing routes based on latency, not health. Option D is wrong because geolocation routes based on geographic location.

Answer

Latency routing policy

Answer

Weighted routing policy

Answer

Geolocation routing policy

Question 4

A SysOps administrator is designing a disaster recovery strategy for a critical application that runs on EC2 instances. The application data is stored on EBS volumes. The recovery point objective (RPO) is 15 minutes, and the recovery time objective (RTO) is 1 hour. Which solution meets these requirements MOST cost-effectively?

Accepted Answer

Take EBS snapshots every 15 minutes and copy them to another Region using cross-region snapshot copy.. Option D is correct because EBS snapshots can be taken every 15 minutes (or via Data Lifecycle Manager) and restored quickly to new volumes in another region. Option A is wrong because cross-region replication of EC2 instances is more expensive and complex. Option B is wrong because AMIs do not capture data changes frequently enough. Option C is wrong because S3 is not suitable for live application data.

Answer

Use AWS CloudEndure to continuously replicate the EC2 instances to another Region.

Answer

Use AWS Backup to back up the application data to Amazon S3 every 15 minutes.

Answer

Take hourly AMIs of the instances and copy them to another Region.

Question 5

A company runs a critical application on EC2 instances in an Auto Scaling group. The application stores state information locally on the instance. The SysOps administrator needs to ensure that if an instance fails, the state is not lost. What should the administrator do?

Accepted Answer

Move the state data to an external data store such as ElastiCache or RDS.. Option B is correct because offloading state to ElastiCache or RDS makes the application stateless and resilient to instance failure. Option A is wrong because instance store is ephemeral and data is lost on failure. Option C is wrong because EBS volumes can be preserved but take time to attach, and the state may be outdated. Option D is wrong because SQS is for message queues, not general state storage.

Answer

Attach an EBS volume and set the 'DeleteOnTermination' flag to false.

Answer

Use instance store volumes for the state data.

Answer

Use Amazon SQS to store the state data.

Question 6

A company has an application that runs on EC2 instances behind an Application Load Balancer. The application uses an RDS Multi-AZ database. The company wants to ensure that the application remains available during a database failover. What should the SysOps administrator do?

Accepted Answer

Ensure the application retries database connections during failover.. Option A is correct because Multi-AZ automatically fails over to a standby in another AZ, minimizing downtime. Option B is wrong because creating a read replica does not help with failover for writes. Option C is wrong because increasing instance size does not affect database failover. Option D is wrong because enabling termination protection is for EC2, not database failover.

Answer

Create a read replica of the database to offload read traffic.

Answer

Increase the EC2 instance size to handle the load.

Answer

Enable termination protection on the EC2 instances.

Question 7

A company is designing a highly available architecture for a web application using AWS services. Which TWO actions should the SysOps administrator take to improve reliability? (Choose TWO.)

Accepted Answer

Use an Auto Scaling group with an Elastic Load Balancer.. Options A and C are correct. Deploying across multiple AZs ensures that the application can withstand an AZ failure. Using an Auto Scaling group with ELB allows automatic scaling and health checks. Option B is wrong because a single instance is a single point of failure. Option D is wrong because a single EBS volume in one AZ is not highly available. Option E is wrong because a single NAT gateway in one AZ is a single point of failure.

Answer

Use a single large EC2 instance to eliminate complexity.

Answer

Use a single NAT gateway for outbound traffic.

Answer

Store application data on a single EBS volume.

Question 8

A company wants to implement a disaster recovery solution for its on-premises database using AWS. The solution must have an RPO of less than 1 hour and an RTO of less than 4 hours. Which THREE steps should the SysOps administrator take? (Choose THREE.)

Accepted Answer

Set up a cross-Region read replica for the RDS instance.. Options B, C, and E are correct. AWS DMS can replicate data continuously to RDS, meeting RPO. RDS with Multi-AZ provides automatic failover. An RDS read replica in another Region provides cross-region failover. Option A is wrong because S3 is not suitable for live database replication. Option D is wrong because EC2 with self-managed replication is more complex and may not meet RTO.

Answer

Launch an EC2 instance with the database software and configure replication.

Answer

Use AWS DataSync to sync the database files to Amazon S3.

Question 9

A company wants to protect its data in Amazon S3 from accidental deletion. Which TWO methods should the SysOps administrator use? (Choose TWO.)

Accepted Answer

Enable S3 Versioning on the bucket.. Options A and C are correct. S3 Versioning preserves previous versions of objects, allowing recovery from accidental deletes. MFA Delete adds an extra layer of protection. Option B is wrong because S3 Transfer Acceleration is for upload speed. Option D is wrong because S3 cross-region replication does not prevent deletion; it replicates objects. Option E is wrong because S3 event notifications do not prevent deletion.

Answer

Set up cross-Region replication.

Answer

Enable S3 Transfer Acceleration.

Answer

Configure S3 event notifications.

Question 10

A company runs a critical e-commerce application on Amazon ECS with Fargate launch type, fronted by an Application Load Balancer. The application uses an Amazon ElastiCache for Redis cluster for session state and an Amazon RDS for MySQL Multi-AZ database for persistent data. Recently, during a deployment of a new service version, the application became unresponsive for 15 minutes. The SysOps administrator discovered that the deployment updated the task definition with a new environment variable that pointed to an incorrect ElastiCache endpoint. The ECS service was configured with a rolling update, minimum healthy percent of 50%, and maximum percent of 200%. After the deployment, all tasks failed health checks due to a connection timeout to the wrong Redis endpoint. What is the MOST effective way to prevent this issue in future deployments?

Accepted Answer

Implement a blue/green deployment strategy using AWS CodeDeploy and test the new task definition before shifting traffic.. Option B is correct. Using AWS CodeDeploy with a blue/green deployment strategy allows testing the new task definition with a new target group before switching traffic. If health checks fail, traffic is not shifted. Option A is wrong because CloudWatch alarms alert but do not prevent the deployment. Option C is wrong because updating one task first still risks the entire deployment if the variable is wrong. Option D is wrong because Circuit breaker only rolls back after failure, not preventing impact.

Answer

Configure a CloudWatch alarm that triggers an automatic rollback if the error rate exceeds 10%.

Answer

Update the ECS service to use a canary deployment by updating one task at a time.

Answer

Enable ECS deployment circuit breaker and set the rollback configuration to automatically roll back failed deployments.

Question 11

A company runs a web application on EC2 instances in an Auto Scaling group across two Availability Zones. The application uses an Application Load Balancer. The SysOps administrator receives an alert that the application is returning 503 errors. The administrator checks the CloudWatch metrics and sees that the ALB's RequestCount is normal, but the HealthyHostCount is zero. The EC2 instances are in running state and pass the EC2 status checks. What is the MOST likely cause and what should the administrator do to resolve the issue?

Accepted Answer

The ALB health check configuration is incorrect; verify the health check path and port.. Option C is correct. The ALB health checks are failing. The most likely cause is that the health check path is wrong or the application is not responding on the configured port. The administrator should verify the health check settings. Option A is wrong because the instances are running and passing EC2 checks. Option B is wrong because security group rules would affect connectivity, but the instances are running. Option D is wrong because scaling policies do not affect health checks.

Answer

The instances are out of memory; increase the instance size.

Answer

The Auto Scaling group's scaling policy is not launching new instances; update the policy.

Answer

The security group on the instances is blocking traffic from the ALB; update the security group.

Question 12

A company runs a critical web application on EC2 instances behind an Application Load Balancer in a single Availability Zone. To improve reliability, what is the MOST effective design change?

Accepted Answer

Launch EC2 instances across two or more Availability Zones.. Option C is correct because deploying instances across multiple Availability Zones eliminates a single point of failure and is a fundamental high-availability design. Option A is wrong because increasing instance size does not provide fault tolerance. Option B is wrong because a Multi-AZ RDS instance improves database reliability but does not address the web tier's single AZ risk. Option D is wrong because an additional load balancer in the same AZ does not protect against AZ failure.

Answer

Place the RDS database in a Multi-AZ deployment.

Answer

Add a second Application Load Balancer in the same Availability Zone.

Answer

Increase the EC2 instance size to handle more traffic.

Question 13

A company's S3 bucket contains critical data. The bucket policy accidentally allowed public write access, and a malicious actor uploaded several objects. The company needs to recover the bucket to a known good state as quickly as possible. What should the SysOps administrator do?

Accepted Answer

Use S3 Versioning to restore the bucket to a previous version.. Option B is correct because S3 Versioning, when enabled, retains all object versions, allowing restoration to a previous state by deleting the current version. Option A is wrong because S3 Object Lock prevents deletion but does not allow rollback to a prior version. Option C is wrong because MFA Delete does not help with restoring prior versions. Option D is wrong because S3 Cross-Region Replication does not provide version rollback capability.

Answer

Enable S3 Object Lock on the bucket to prevent further modifications.

Answer

Enable MFA Delete on the bucket to secure delete operations.

Answer

Configure S3 Cross-Region Replication to replicate data to another region.

Question 14

A SysOps administrator needs to ensure that an EC2 instance automatically recovers from an underlying hardware failure. Which action should be taken?

Accepted Answer

Create a CloudWatch alarm on the StatusCheckFailed metric and configure the recovery action.. Option B is correct because configuring the EC2 instance with a CloudWatch alarm based on StatusCheckFailed will trigger a recovery action that stops and starts the instance on new hardware. Option A is wrong because Auto Scaling groups manage instance counts but do not recover a specific instance. Option C is wrong because Elastic IP reassignment does not recover the instance. Option D is wrong because a second instance does not automatically recover the original.

Answer

Launch a second instance in a different Availability Zone.

Answer

Assign an Elastic IP address to the instance.

Answer

Place the instance in an Auto Scaling group with a min size of 1.

Question 15

A company uses AWS Backup to back up its Amazon EFS file systems. The SysOps administrator needs to ensure that backups are retained for 7 years to meet compliance requirements. What should the administrator do?

Accepted Answer

Create a backup plan with a lifecycle policy that retains backups for 7 years.. Option C is correct because AWS Backup lifecycle policies allow you to transition backups to cold storage after a specified period and define retention rules up to 100 years. Option A is wrong because increasing backup frequency does not affect retention duration. Option B is wrong because cross-region backup does not extend retention. Option D is wrong because manual deletion is not automated and does not enforce compliance.

Answer

Manually delete backups older than 7 years every month.

Answer

Increase the backup frequency to daily.

Answer

Configure cross-region backup to copy backups to another region.