SOA-C02 Mock Exam 72 — 25 Questions

Question 1

An Auto Scaling group launches new EC2 instances when CPU exceeds 70 percent. The instances take 4 minutes to bootstrap (install software, register with a service discovery system, and warm up caches). Without a hook, the load balancer routes traffic to new instances before they are ready, causing 503 errors. What is the correct solution?

Accepted Answer

Add a lifecycle hook on the autoscaling:EC2_INSTANCE_LAUNCHING transition; signal CompleteLifecycleAction(CONTINUE) when bootstrap finishes. Option A is correct because lifecycle hooks allow the Auto Scaling group to pause instance launch until a custom action (e.g., bootstrap completion) is finished. By adding a hook on the autoscaling:EC2_INSTANCE_LAUNCHING transition, the instance is held in a 'pending:wait' state. Once the bootstrap script calls CompleteLifecycleAction with the CONTINUE result, the instance transitions to 'InService' and can then be registered with the load balancer, preventing premature traffic and 503 errors.

Answer

Increase the load balancer health check grace period to 10 minutes to give instances time to bootstrap

Answer

Increase the warm-up time in the Auto Scaling group's instance refresh configuration

Answer

Use a weighted target group with 0 weight for new instances until they are confirmed healthy

Question 2

Regulatory requirements mandate that all RDS and EBS backups are replicated to a secondary AWS region within 24 hours of creation. The company has workloads in us-east-1 and must replicate backups to eu-west-1. Restoring from the secondary region must be possible without manual copying steps during a disaster. What service and configuration implements this requirement?

Accepted Answer

Create an AWS Backup plan with a cross-Region copy rule that replicates recovery points to a backup vault in eu-west-1 within 24 hours. AWS Backup is the correct service because it natively supports cross-Region copy rules that automatically replicate recovery points (including RDS snapshots and EBS snapshots) to a backup vault in a secondary Region within a specified time window. This meets the 24-hour replication requirement and enables direct restores from the secondary Region without manual copying, as the backup vault in eu-west-1 contains the replicated recovery points ready for use.

Answer

Schedule a Lambda function that calls CreateDBSnapshot and CopyDBSnapshot to replicate RDS snapshots, and CreateSnapshot and CopySnapshot for EBS volumes to eu-west-1

Answer

Enable RDS automated backups with cross-region replication and configure EBS snapshot copy separately using Data Lifecycle Manager

Answer

Use S3 Cross-Region Replication to replicate the backup bucket containing RDS and EBS snapshots to eu-west-1

Question 3

An EC2 instance runs a database on a 2 TB EBS gp3 volume. After a corruption event, the team must restore from a snapshot. When they detach the corrupted volume, attach a new volume restored from the snapshot, and start the database, performance is 10 to 20 times lower than normal for the first two hours. What causes this behavior, and what feature eliminates it?

Accepted Answer

Enable Fast Snapshot Restore (FSR) on the snapshot in the target Availability Zone before creating the replacement volume. When you create an EBS volume from a snapshot, the volume's data blocks are lazily loaded from Amazon S3 on first access. This causes high latency and low IOPS until all blocks are fetched. Fast Snapshot Restore (FSR) pre-initializes the volume in a specific Availability Zone, eliminating the need for lazy loading and providing full performance immediately.

Answer

Use a Provisioned IOPS (io2) volume type instead of gp3 to get higher IOPS during initialization

Answer

Run a full dd or fio pre-warm pass over the volume after attaching it but before starting the database

Answer

Increase the EBS volume size to 4 TB when restoring from the snapshot to get double the throughput baseline

Question 4

A company runs a stateless web application on Amazon EC2 instances in an Auto Scaling group across two Availability Zones. The SysOps administrator needs to ensure that the application can tolerate a failure of an entire Availability Zone. Which configuration is required?

Accepted Answer

Use an Application Load Balancer (ALB) that spans both Availability Zones with health checks enabled.. An Application Load Balancer (ALB) that spans both Availability Zones with health checks enabled distributes incoming traffic across EC2 instances in multiple AZs. If an entire AZ fails, the ALB automatically routes traffic only to healthy instances in the remaining AZ, ensuring the stateless web application remains available. Health checks detect instance or AZ failure and remove unhealthy targets from the load balancer's target group, which is essential for fault tolerance.

Answer

Enable termination protection on all Amazon EC2 instances.

Answer

Place the Amazon EC2 instances in a cluster placement group.

Answer

Associate an Elastic IP address with the primary instance.

Question 5

A company runs a production Amazon RDS for PostgreSQL DB instance. The SysOps administrator needs to ensure that in the event of a database failure, there is automatic failover to a standby instance in another Availability Zone with minimal downtime. Which deployment configuration should the administrator enable?

Accepted Answer

Multi-AZ deployment. A Multi-AZ deployment for Amazon RDS automatically provisions and maintains a synchronous standby replica in a different Availability Zone. In the event of a database failure or an Availability Zone outage, Amazon RDS automatically fails over to the standby, typically within 60-120 seconds, without requiring manual intervention. This ensures high availability and minimal downtime for the production PostgreSQL DB instance.

Answer

Read Replicas

Answer

Automated backups with point-in-time recovery

Answer

Amazon RDS Proxy

Question 6

A company runs a critical application on Amazon EC2 instances. The application uses an NFS file system stored on an Amazon EFS file system. The SysOps administrator must ensure that the file system is highly available and can withstand an Availability Zone failure. The file system must be accessible from all Availability Zones in the region. Which configuration is required to meet these requirements?

Accepted Answer

Configure the EFS file system for Standard storage class and mount it using the regional DNS name.. Option B is correct because the EFS Standard storage class replicates data across multiple Availability Zones (AZs) within a region, providing high availability and resilience against an AZ failure. Mounting the file system using the regional DNS name ensures that clients in any AZ can reach the file system via the nearest mount target, as the regional DNS name resolves to the mount target IP addresses in the local AZ. This configuration meets the requirement for the file system to be accessible from all AZs in the region while withstanding an AZ outage.

Answer

Configure the EFS file system for One Zone storage class and mount it using the file system ID.

Answer

Configure EFS to use provisioned throughput and mount it using a mount target IP address.

Answer

Enable EFS lifecycle management to move files to Infrequent Access storage class.

Question 7

Match each AWS storage service to its description.

Question 8

Drag and drop the steps to set up an AWS Site-to-Site VPN connection into the correct order.

Question 9

A company runs a critical database workload on an Amazon RDS for MySQL DB instance with Multi-AZ deployment in the us-east-1 region. The SysOps administrator must design a disaster recovery strategy that can recover from a complete regional outage. The Recovery Time Objective (RTO) is 2 hours and the Recovery Point Objective (RPO) is 1 hour. Which solution meets these requirements at the lowest cost?

Accepted Answer

Create a cross-Region read replica in another Region and promote it to a standalone DB instance during a disaster.. Option C is correct because a cross-Region read replica continuously replicates data from the primary RDS MySQL instance to another Region with minimal lag, typically achieving an RPO of seconds to minutes, well within the 1-hour requirement. Promoting the replica to a standalone instance during a disaster can be done in minutes, meeting the 2-hour RTO. This approach is the lowest cost among the viable options as it uses existing replication infrastructure without additional data transfer fees for snapshots or DMS replication instances.

Answer

Create manual snapshots of the DB instance every hour and copy them to another AWS Region.

Answer

Enable automated backups with a retention period of 35 days and restore to a different Region when needed.

Answer

Use AWS Database Migration Service (DMS) to continuously replicate data to a DB instance in another Region.

Question 10

A company runs a critical web application on a single Amazon EC2 instance with a 100 GiB gp2 EBS volume. The SysOps administrator needs to ensure data durability by taking automated snapshots of the root volume every hour. The snapshots should be retained for 7 days. Which AWS service can be used to automate this task with minimal configuration?

Accepted Answer

Amazon Data Lifecycle Manager (DLM). Amazon Data Lifecycle Manager (DLM) is the correct choice because it is specifically designed to automate the creation, retention, and deletion of EBS snapshots with minimal configuration. It supports custom schedules (e.g., every hour) and retention policies (e.g., 7 days) directly on EBS volumes, making it ideal for this task without requiring additional scripting or infrastructure.

Answer

AWS Backup

Answer

Amazon CloudWatch Events

Answer

AWS Systems Manager

Question 11

A company runs an Amazon RDS for MySQL DB instance in us-east-1. The SysOps administrator needs to implement a disaster recovery solution that can recover from a regional outage with a Recovery Point Objective (RPO) of less than 1 second and a Recovery Time Objective (RTO) of less than 1 minute. Which solution should the administrator use?

Accepted Answer

Aurora Global Database. Aurora Global Database is the correct choice because it provides a fully managed cross-region replication solution with a typical RPO of less than 1 second and an RTO of less than 1 minute during a regional failover. It uses a primary cluster in one region and up to five secondary clusters in other regions, with asynchronous replication that is optimized for low latency, meeting the stringent RPO/RTO requirements.

Answer

Multi-AZ deployment

Answer

Cross-region read replica

Answer

Automated snapshot copy to another region

Question 12

A company has an Amazon DynamoDB table with on-demand capacity mode. The SysOps administrator needs to ensure that the table can survive a regional outage. The table is currently in us-east-1. Which feature should be configured to achieve regional resilience with minimal data loss?

Accepted Answer

DynamoDB global tables. DynamoDB global tables provide multi-Region, fully replicated tables that automatically propagate writes to all configured Regions, enabling the table to survive a regional outage with minimal data loss. This feature uses DynamoDB Streams to replicate data asynchronously across Regions, offering recovery point objectives (RPO) of typically under one second. For the requirement of regional resilience, global tables are the correct choice because they maintain active copies in multiple AWS Regions.

Answer

DynamoDB Accelerator (DAX)

Answer

DynamoDB point-in-time recovery

Answer

DynamoDB auto scaling

Question 13

A company runs a critical web application on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer (ALB). The application uses session stickiness (sticky sessions) to maintain user sessions. The SysOps administrator notices that when instances are replaced during a scale-in or failure event, users lose their session data. The administrator needs to preserve session data across instance failures without losing stickiness benefits. What should the administrator do?

Accepted Answer

Disable sticky sessions on the ALB and configure the application to store session data in an external session store like Amazon ElastiCache for Redis.. Option A is correct because storing session data externally in a service like Amazon ElastiCache for Redis decouples session state from the EC2 instance lifecycle. This allows the ALB to continue using sticky sessions to route a user to the same instance, but if that instance fails or is replaced, the new instance can retrieve the session data from the shared Redis cache, preserving the user's session without interruption.

Answer

Increase the stickiness duration to a very high value so that sessions are not lost during brief interruptions.

Answer

Change the Auto Scaling group to use a larger instance type to handle more sessions per instance, reducing the likelihood of session loss.

Answer

Configure the Auto Scaling group to use a larger minimum size and a lower maximum, so instances are less likely to be terminated.

Question 14

A company has a production Amazon RDS for MySQL DB instance in a single Availability Zone. The SysOps administrator needs to improve database availability to ensure automatic failover in the event of a database failure or an Availability Zone outage. Which configuration should the administrator enable?

Accepted Answer

Enable Multi-AZ deployment. Enabling a Multi-AZ deployment for Amazon RDS for MySQL automatically provisions and maintains a synchronous standby replica in a different Availability Zone. In the event of a database failure or an AZ outage, Amazon RDS automatically fails over to the standby replica, typically within 60–120 seconds, without requiring manual intervention. This configuration meets the requirement for automatic failover and improved availability.

Answer

Create a read replica in another Availability Zone

Answer

Enable automated backups

Answer

Change the DB instance to a larger instance class

Question 15

A company has an Amazon RDS for PostgreSQL DB instance with Multi-AZ deployment in us-east-1. The SysOps administrator must design a disaster recovery strategy to recover from a regional outage. The Recovery Time Objective (RTO) is 1 hour and the Recovery Point Objective (RPO) is 5 minutes. Which solution meets these requirements at the lowest cost?

Accepted Answer

Create a Read Replica in a different region and promote it during a disaster.. A cross-region Read Replica meets the RPO of 5 minutes because replication is continuous (asynchronous) with minimal lag, and the RTO of 1 hour is achievable by promoting the replica during a disaster. This is the lowest-cost option because it uses a single standby instance in another region without the overhead of a full Multi-AZ deployment or frequent snapshot transfers.

Answer

Take daily snapshots and copy them to another region.

Answer

Use cross-region automated backups.

Answer

Deploy a second Multi-AZ DB instance in another region.

Question 16

A company runs a critical application on Amazon ECS with the Fargate launch type. The application must remain available if a single Availability Zone fails. The SysOps administrator needs to configure the ECS service for high availability. Which configuration should be used?

Accepted Answer

Use a spread placement strategy across multiple Availability Zones.. Option B is correct because using a spread placement strategy across multiple Availability Zones ensures that ECS tasks are distributed across distinct zones, so the application remains available if a single zone fails. With Fargate, the spread strategy can be applied at the Availability Zone level, and ECS automatically manages task placement to maintain the desired distribution. This configuration meets the high availability requirement by eliminating a single point of failure at the zone level.

Answer

Place tasks in a single Availability Zone.

Answer

Use a binpack placement strategy.

Answer

Increase the desired task count to 10.

Question 17

A company runs a critical production database on Amazon RDS for MySQL with a Multi-AZ deployment. The database experiences a primary instance failure. The SysOps administrator needs to understand exactly how the failover process worked and why the application experienced a longer-than-expected downtime. Which AWS service or feature should the administrator use to review detailed events and actions during the failover?

Accepted Answer

AWS Personal Health Dashboard. AWS Personal Health Dashboard provides a personalized view of the health of AWS services and resources, including detailed event logs for RDS Multi-AZ failovers. It surfaces the exact sequence of actions (e.g., DNS record update, failover initiation, completion) and any underlying AWS infrastructure issues that caused the extended downtime, such as degraded hardware or network latency. This is the correct tool because it gives the administrator a chronological, AWS-side account of the failover process, which is not available through other services.

Answer

Amazon RDS Performance Insights

Answer

Amazon CloudWatch Logs

Answer

AWS CloudTrail

Question 18

A company runs a global e-commerce application that uses Amazon DynamoDB as its primary database. The application requires single-digit millisecond read and write latency from any region and must continue to operate during a regional outage with minimal data loss. Which DynamoDB feature should the SysOps administrator enable to meet these requirements?

Accepted Answer

DynamoDB global tables. DynamoDB global tables provide multi-Region, multi-active replication, enabling single-digit millisecond reads and writes from any Region while offering automatic failover and recovery during a regional outage. This feature uses DynamoDB Streams to replicate data across Regions with eventual consistency, meeting the requirement for continued operation with minimal data loss.

Answer

DynamoDB Accelerator (DAX)

Answer

DynamoDB Point-in-Time Recovery (PITR)

Answer

DynamoDB Auto Scaling

Question 19

A company runs a stateful web application on a single Amazon EC2 instance. The application stores session state in memory and writes critical data to an Amazon EBS volume. The SysOps administrator needs to implement a highly available architecture that can tolerate an Availability Zone (AZ) failure. The administrator plans to use an Auto Scaling group and an Application Load Balancer (ALB). Which combination of steps is required to make the application highly available while preserving session and data durability across AZ failures?

Accepted Answer

Use an Auto Scaling group across multiple AZs, migrate session storage to Amazon ElastiCache (multi-AZ), and migrate application data from EBS to Amazon EFS (file system mounted across AZs).. Option C is correct because it addresses both session state and data durability across AZ failures. Migrating session storage to ElastiCache (multi-AZ) ensures session data survives instance failure, and migrating application data from EBS to EFS provides a shared, multi-AZ file system that persists independently of any single EC2 instance. This combination allows the Auto Scaling group to launch new instances in any AZ and immediately access both session and application data.

Answer

Create an AMI of the current instance, configure an Auto Scaling group with a launch template that uses the AMI, and attach the existing EBS volume to new instances.

Answer

Create a multi-AZ Auto Scaling group and use sticky sessions (session affinity) on the ALB to tie users to specific instances.

Answer

Use an Auto Scaling group in a single AZ and use a Multi-AZ RDS instance for data storage.

Question 20

A company runs a stateful web application on a single Amazon EC2 instance. The SysOps administrator needs to implement a high availability architecture that can tolerate an Availability Zone (AZ) failure. The application stores session state in memory and also writes critical data to an Amazon EBS volume. The administrator wants to use an Auto Scaling group and an Application Load Balancer (ALB). Which combination of steps is required to make the application highly available?

Accepted Answer

Migrate session state to Amazon ElastiCache for Redis, store critical data in Amazon EFS, create an Auto Scaling group across multiple AZs, and place it behind an ALB.. Option B is correct because it addresses both the stateless requirement for horizontal scaling and the persistence of critical data across AZ failures. Migrating session state to ElastiCache for Redis removes the dependency on local instance memory, allowing any instance to handle any request. Storing critical data on Amazon EFS provides a shared, NFS-based file system that is accessible from all instances across multiple AZs, unlike EBS which is tied to a single AZ. Combining these with a multi-AZ Auto Scaling group and an ALB ensures the application can survive an entire AZ outage.

Answer

Create an Auto Scaling group that spans at least two Availability Zones, attach the existing EBS volume to the new instances, and use an ALB to distribute traffic.

Answer

Place the EC2 instance in an Auto Scaling group with a minimum and maximum of 1 in the same AZ, and attach an Elastic IP to the instance.

Answer

Use an ALB with the existing single instance as the target, and enable cross-zone load balancing.