SOA-C02 Practice Test 25 — 15 Questions

Question 1

A SysOps administrator wants to back up an Amazon EBS volume that is attached to an EC2 instance running a production database. The backup must be crash-consistent and should not cause any downtime. Which TWO steps should the administrator take? (Choose two.)

Accepted Answer

Take a snapshot of the EBS volume after freezing.. Options B and D are correct. To ensure crash consistency, the database should be frozen (e.g., via fsync) and I/O paused. Then take a snapshot of the volume. Option A is incorrect because taking a snapshot of a running volume without freezing may result in an inconsistent backup. Option C is incorrect because stopping the instance causes downtime. Option E is incorrect because detaching the volume causes downtime.

Answer

Stop the EC2 instance before taking the snapshot.

Answer

Take a snapshot directly from the attached volume without any preparation.

Answer

Detach the volume from the instance before taking a snapshot.

Question 2

A company is designing a disaster recovery strategy for its production database hosted on Amazon RDS for MySQL. The primary database is in us-east-1. The company requires an RPO of less than 5 minutes and an RTO of less than 1 hour in the event of a Regional failure. Which TWO actions should the company take to meet these requirements?

Accepted Answer

Create a cross-Region Read Replica in us-west-2 and promote it during a disaster.. Options B and D are correct. Enabling cross-Region automated backups (Option B) provides continuous backup to another Region with low RPO. Option D, creating a cross-Region Read Replica and promoting it, allows fast failover with low RTO. Option A (Multi-AZ) is for AZ-level failure, not regional. Option C (snapshots) has higher RPO. Option E (single-AZ) does not provide failover.

Answer

Take daily manual snapshots and copy them to us-west-2.

Answer

Enable Multi-AZ deployment for the RDS instance.

Answer

Use a single-AZ RDS instance with automated backups.

Question 3

A company has a production RDS for PostgreSQL instance. They need to recover from a logical corruption that occurred 2 hours ago. Which recovery method will minimize data loss?

Accepted Answer

Perform a point-in-time recovery to a time just before the corruption occurred.. Option A is correct because point-in-time recovery can restore to any time within the backup retention period, allowing recovery to just before the corruption. Option B is wrong because a snapshot from 1 hour ago would include the corruption. Option C is wrong because a read replica contains the corruption if it was replicated. Option D is wrong because a full database restore from backup is less precise.

Answer

Restore from the latest automated snapshot taken 1 hour ago.

Answer

Use pg_dump to export the database and restore it.

Answer

Fail over to the read replica in another AZ.

Question 4

A company has a critical application running on EC2 instances in an Auto Scaling group behind an ALB. The application uses a custom health check endpoint at /health. The SysOps administrator notices that the ALB occasionally marks instances as unhealthy even though the application is running correctly. The health check settings are: HealthCheckIntervalSeconds=30, HealthyThresholdCount=5, UnhealthyThresholdCount=2. What is the most likely cause of the intermittent health check failures?

Accepted Answer

The HealthyThresholdCount is set too high, causing instances to remain unhealthy after transient issues.. Option C is correct: With HealthyThresholdCount=5, an instance must pass 5 consecutive health checks to be marked healthy. If the health check endpoint returns a single 5xx error due to a transient issue, the instance may be considered unhealthy for a prolonged period. Option A is incorrect because TCP health checks are less granular but would not cause intermittent failures if the instance is reachable. Option B is incorrect because an UnhealthyThresholdCount of 2 is standard and not too low. Option D is incorrect because 5xx errors are not ignored by ALB health checks.

Answer

The health check endpoint returns 5xx errors, which are ignored by the ALB.

Answer

The UnhealthyThresholdCount is set too low.

Answer

The health check is using TCP instead of HTTP.

Question 5

A SysOps administrator is designing a disaster recovery plan for a critical application hosted on AWS. The application runs on EC2 instances with data stored in an RDS MySQL database. The RPO must be less than 15 minutes, and the RTO must be less than 1 hour. Which solution meets these requirements?

Accepted Answer

Use an RDS Multi-AZ DB Cluster deployment.. Option D is correct because Multi-AZ DB Cluster provides automatic failover with low RPO and RTO, and synchronous replication keeps data consistent. Option A is wrong because single-AZ with snapshots has an RPO of up to 5 minutes and RTO of several hours. Option B is wrong because Read Replicas are asynchronous, leading to potential data loss. Option C is wrong because Daily snapshots do not meet the 15-minute RPO.

Answer

Take daily snapshots of the RDS instance and copy them to another Region.

Answer

Use an RDS DB instance with a Multi-AZ standby and a cross-Region Read Replica.

Answer

Use a single-AZ RDS instance with automated backups and point-in-time recovery.

Question 6

A company has a production application running on Amazon ECS with Fargate. The application must be highly available across multiple Availability Zones. Which TWO configurations should be implemented?

Accepted Answer

Configure the ECS service to run tasks in at least two Availability Zones.. Options A and C are correct. Using an Application Load Balancer (Option A) distributes traffic across tasks. Running tasks in multiple Availability Zones (Option C) ensures availability if one AZ fails. Option B (single AZ) is not highly available. Option D (network mode) is not related to AZ distribution. Option E (spot) is not for high availability.

Answer

Configure the ECS service to run tasks in a single Availability Zone to reduce network latency.

Answer

Use the awsvpc network mode for the task definition.

Answer

Use Fargate Spot capacity providers to reduce costs.

Question 7

Which TWO actions improve the availability of an application running on EC2 instances in a single Auto Scaling group? (Choose 2)

Accepted Answer

Use an Elastic Load Balancer with health checks to route traffic only to healthy instances.. Options A and B are correct. Distributing instances across multiple AZs and configuring ELB health checks are fundamental high availability practices. Option C is wrong because increasing instance size does not improve availability. Option D is wrong because CloudWatch alarms alert but do not automatically improve availability. Option E is wrong because EBS optimization improves performance, not availability.

Answer

Increase the instance size to handle higher load.

Answer

Create a CloudWatch alarm to notify when the CPU utilization exceeds 80%.

Answer

Enable EBS optimization on the instances.

Question 8

A company runs a production database on Amazon RDS for MySQL with Multi-AZ enabled. During a recent Availability Zone outage, the database experienced a failover. After the failover, the application team notices that the database endpoint in the connection string no longer works. What is the most likely cause?

Accepted Answer

The application is using the IP address of the database instance instead of the DNS endpoint.. Option A is correct because the DNS name for an RDS instance automatically resolves to the primary instance; after failover, the DNS is updated to point to the new primary, so the endpoint should still work. Option B is wrong because the CNAME is automatically updated by AWS. Option C is wrong because the DB instance identifier does not change. Option D is wrong because the security group rules apply to the RDS instance, not the connection string.

Answer

The DB instance identifier changed after the failover.

Answer

The security group for the RDS instance was modified during the failover.

Answer

The DNS CNAME record for the RDS endpoint was manually changed.

Question 9

A company runs a web application on EC2 instances in an Auto Scaling group behind an Application Load Balancer. The application stores session data on local instance storage. Users report that they are unexpectedly logged out during peak traffic. Which action should the SysOps Administrator take to improve reliability?

Accepted Answer

Configure an ElastiCache Redis cluster to store session state externally.. Option C is correct because storing session state in a shared Elasticache cluster provides a central, durable location that survives instance termination. Option A is wrong because it does not address session loss. Option B is wrong because instance store is ephemeral. Option D is wrong because it does not solve the session persistence issue.

Answer

Move the session storage to an instance store volume.

Answer

Enable sticky sessions on the Application Load Balancer.

Answer

Increase the size of the Auto Scaling group to handle peak traffic.

Question 10

A SysOps administrator is designing a disaster recovery plan for a web application that runs on EC2 instances with data stored in an RDS MySQL database. The application requires a Recovery Point Objective (RPO) of 5 minutes and a Recovery Time Objective (RTO) of 1 hour. Which solution meets these requirements most cost-effectively?

Accepted Answer

Use RDS Multi-AZ with automated backups and EC2 AMI backups.. Option C is correct: RDS Multi-AZ with automatic backups provides synchronous standby replication and point-in-time recovery, meeting RPO of 5 minutes. AMI backups of EC2 can be used to launch instances quickly, meeting RTO of 1 hour. Option A is incorrect because read replicas are not used for failover by default; promoting a read replica takes time. Option B is incorrect because standby EC2 in another Region incurs higher costs and complexity. Option D is incorrect because a single RDS instance is a single point of failure.

Answer

Use a single RDS instance with daily snapshots and EC2 instance store.

Answer

Use EC2 Auto Scaling across Regions with an RDS standby instance.

Answer

Use RDS Multi-AZ with read replicas in another Region.

Question 11

An application runs on EC2 instances in an Auto Scaling group. The instances process messages from an SQS queue. To ensure high availability, the SysOps administrator has configured the Auto Scaling group to span three Availability Zones. However, during a recent failure of one AZ, the application experienced a temporary increase in processing latency. What is the MOST likely cause of this latency?

Accepted Answer

SQS messages in the failed AZ are temporarily unavailable until they are replicated to other AZs.. Option D is correct because the SQS queue is a regional service, but the messages are distributed across AZs. When one AZ fails, messages in that AZ may become temporarily unavailable until they are replicated, causing a delay in processing. Option A is wrong because the Auto Scaling group is already configured to span three AZs. Option B is wrong because SQS automatically replicates across AZs. Option C is wrong because the application should be able to process messages from remaining AZs.

Answer

The SQS queue is configured to use a single AZ for message storage.

Answer

The application is not configured to process messages from multiple AZs.

Answer

The Auto Scaling group's minimum size is too low to handle the load after the AZ failure.

Question 12

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

Accepted Answer

Create a CloudWatch alarm on the StatusCheckFailed metric and configure the recovery action.. Option C is correct because a CloudWatch alarm based on the StatusCheckFailed metric can trigger a recovery action. Option A is wrong because Auto Scaling recovery terminates and replaces the instance, which may change the private IP. Option B is wrong because termination protection only prevents accidental deletion. Option D is wrong because a Lambda function is unnecessary and more complex.

Answer

Use AWS Lambda to periodically check instance health and reboot if necessary.

Answer

Enable termination protection on the instance.

Answer

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

Question 13

A SysOps administrator runs the above command for an EC2 instance. The instance is running but the system status check is impaired. What does this indicate?

Accepted Answer

There is a problem with the underlying physical host that requires stopping and starting the instance.. Option C is correct because a system status check failure indicates a problem with the underlying physical host or AWS systems. Option A is wrong because instance status checks are separate. Option B is wrong because system status checks cover the host, not the OS. Option D is wrong because the instance status is 'ok', so the OS is reachable.

Answer

The instance is still running but the application is not responding.

Answer

The instance is unreachable due to a misconfigured security group.

Answer

The operating system on the instance has crashed.

Question 14

A company runs a web application on EC2 instances in an Auto Scaling group behind an Application Load Balancer. The application stores session data locally on each instance. During a traffic spike, the Auto Scaling group launches new instances, but users report that they are logged out and lose session data. Which solution addresses this issue without modifying the application?

Accepted Answer

Enable sticky sessions (session affinity) on the Application Load Balancer.. Option D is correct because enabling sticky sessions on the ALB ensures that users are routed to the same instance, preserving session data even as instances are added or removed. Option A is wrong because increasing the cooldown period does not preserve sessions during scaling. Option B is wrong, while it offloads state to ElastiCache, it requires application changes. Option C is wrong because a larger instance size reduces scaling frequency but does not prevent session loss when instances are terminated.

Answer

Modify the application to use ElastiCache for session storage.

Answer

Increase the cooldown period for the Auto Scaling group.

Answer

Use larger EC2 instance types to handle the traffic spike.

Question 15

A company wants to ensure that its Amazon RDS database can withstand the loss of an entire Availability Zone. Which feature should the SysOps administrator enable?

Accepted Answer

Enable Multi-AZ deployment.. Option B is correct: Multi-AZ deployment creates a standby in a different AZ; if the primary AZ fails, RDS automatically fails over to the standby. Option A is incorrect because read replicas can be in a different AZ but are not used for automatic failover. Option C is incorrect because manual snapshots require manual restoration. Option D is incorrect because automated backups are stored in S3 and do not provide automatic failover.

Answer

Enable automated backups with a retention period of 35 days.

Answer

Take manual snapshots and copy them to another Region.

Answer

Create a read replica in a different Availability Zone.