SOA-C02 Reliability and Business Continuity Practice Test 8 — 15 Questions

Question 1

A company uses S3 to store critical data. They need to ensure that data can be recovered in the event of accidental deletion or overwriting by users. Which combination of actions should they take?

Accepted Answer

Enable S3 Versioning and MFA Delete.. Enabling S3 Versioning preserves all versions of an object, allowing recovery from accidental deletion or overwriting. MFA Delete adds an extra layer of protection by requiring multi-factor authentication to permanently delete object versions or suspend versioning, preventing unauthorized or accidental permanent data loss.

Answer

Enable S3 Cross-Region Replication and S3 Transfer Acceleration.

Answer

Enable S3 Versioning and S3 Transfer Acceleration.

Answer

Enable S3 Server Access Logging and S3 Object Lock.

Question 2

A SysOps administrator is setting up a backup plan for an RDS MySQL database. The database is 500 GB in size and is used for a critical application. The company requires a Recovery Point Objective (RPO) of 5 minutes and a Recovery Time Objective (RTO) of 1 hour. Which solution meets these requirements?

Accepted Answer

Deploy the RDS instance in a Multi-AZ configuration with automatic failover.. Multi-AZ RDS with automatic failover meets the RPO of 5 minutes and RTO of 1 hour because it synchronously replicates data to a standby instance in a different Availability Zone. In the event of a failure, Amazon RDS automatically fails over to the standby, typically completing within 60–120 seconds, which satisfies the RTO. The synchronous replication ensures zero data loss (RPO of effectively 0), well within the 5-minute requirement.

Answer

Use AWS Backup to copy snapshots to a different AWS Region.

Answer

Take manual snapshots every 5 minutes and store them in Amazon S3.

Answer

Configure a cross-region read replica and promote it during failover.

Question 3

An application running on EC2 instances stores session data in an attached EBS volume. The company wants to ensure session data is not lost if an instance fails. Which solution should the administrator implement?

Accepted Answer

Move session storage to Amazon ElastiCache for Redis with replication.. Amazon ElastiCache for Redis with replication provides a highly available, in-memory data store that persists session data independently of EC2 instances. If an instance fails, the session data remains intact in the replicated Redis cluster, ensuring zero data loss and seamless failover. This decouples session state from ephemeral compute resources, aligning with the reliability and business continuity requirements.

Answer

Use EBS Multi-Attach to attach the volume to multiple instances.

Answer

Take frequent EBS snapshots of the volume.

Answer

Use a larger EC2 instance type with more memory.

Question 4

A company runs a critical application on EC2 instances in an Auto Scaling group with a minimum of 2 instances. The instances are in a single Availability Zone. The company wants to achieve 99.99% availability. Which change should they make?

Accepted Answer

Modify the Auto Scaling group to launch instances in multiple Availability Zones and place an Application Load Balancer in front.. To achieve 99.99% availability, the application must survive an Availability Zone (AZ) failure. Running instances in a single AZ creates a single point of failure. By modifying the Auto Scaling group to launch instances in multiple AZs and placing an Application Load Balancer (ALB) in front, traffic is automatically distributed across healthy instances in different AZs, ensuring fault tolerance even if an entire AZ becomes unavailable.

Answer

Increase the minimum size of the Auto Scaling group to 4 instances.

Answer

Use a larger EC2 instance type to handle more traffic.

Answer

Configure the Auto Scaling group to scale based on memory utilization.

Question 5

A company is designing a disaster recovery plan for its on-premises database. They need to replicate the database to AWS with low latency. Which AWS service should they use?

Accepted Answer

AWS Database Migration Service (DMS) with ongoing replication.. AWS DMS with ongoing replication (change data capture, CDC) is the correct choice because it can continuously replicate changes from an on-premises database to a target database in AWS with low latency, supporting heterogeneous and homogeneous migrations. This meets the requirement for a disaster recovery plan that keeps the AWS copy nearly synchronized with the on-premises source.

Answer

Amazon S3 with Cross-Region Replication.

Answer

AWS Storage Gateway with volume gateway.

Answer

AWS Direct Connect to establish a dedicated network connection.

Question 6

A SysOps administrator needs to ensure that an S3 bucket can recover from accidental deletions by users. The bucket stores versioned objects. What additional configuration should be enabled to prevent permanent deletion?

Accepted Answer

Enable MFA Delete on the bucket.. Enabling MFA Delete on the S3 bucket adds an extra layer of protection by requiring multi-factor authentication for any DeleteObject or DeleteBucket operations. Even if a user has s3:DeleteObject permission, they cannot permanently delete versioned objects unless they present a valid MFA code. This prevents accidental or unauthorized permanent deletions while still allowing versioned objects to be recovered.

Answer

Enable S3 Server-Side Encryption.

Answer

Enable S3 Lifecycle rules to expire objects.

Answer

Configure a bucket policy to deny s3:DeleteObject.

Question 7

A company is running a stateful web application on a single EC2 instance in a public subnet. The instance stores user sessions locally. The company wants to improve availability without rewriting the application. Which design should they use?

Accepted Answer

Deploy an Application Load Balancer across multiple AZs, move session storage to ElastiCache, and use an Auto Scaling group.. It addresses the core issue of stateful sessions without rewriting the application. By moving session storage to ElastiCache (a centralized, external data store), the application becomes stateless from the instance's perspective, allowing an Auto Scaling group across multiple Availability Zones (AZs) and an Application Load Balancer (ALB) to distribute traffic seamlessly. This design improves availability by enabling horizontal scaling and fault tolerance, as any instance can handle any request since sessions are stored externally.

Answer

Create a second EC2 instance in a different AZ and use Route 53 with health checks.

Answer

Use an Auto Scaling group across multiple AZs but keep sessions on instance.

Answer

Use an Application Load Balancer with sticky sessions and an Auto Scaling group in a single AZ.

Question 8

A company has an RDS PostgreSQL database with a Multi-AZ deployment. The primary instance fails. What happens to the application connections?

Accepted Answer

The application must reconnect to the same endpoint; it will be redirected to the standby instance.. When the primary RDS PostgreSQL instance fails in a Multi-AZ deployment, AWS automatically fails over to the standby instance in a different Availability Zone. The DNS endpoint (CNAME) remains the same, but its resolution is updated to point to the standby instance's IP address. The application must reconnect to the same endpoint, as existing connections to the failed primary are dropped; after reconnection, traffic is seamlessly routed to the new primary.

Answer

The application will be automatically redirected to a read replica.

Answer

The administrator must manually change the CNAME to point to the standby.

Answer

The application must use a new endpoint in a different AWS Region.

Question 9

A company wants to back up its on-premises file servers to AWS for disaster recovery. The data changes frequently, and the company needs to minimize data loss. Which THREE steps should the company take? (Select THREE.)

Accepted Answer

Use AWS Backup to create backup plans for the Storage Gateway.. AWS Backup can create backup plans for Storage Gateway volumes and file shares, providing automated, policy-based backups to Amazon S3. This ensures consistent, scheduled backups of the on-premises data cached in the file gateway, minimizing data loss by capturing frequent changes according to the backup plan's schedule.

Answer

Use S3 Transfer Acceleration for uploads.

Answer

Set up S3 Cross-Region Replication from the backup bucket.

Question 10

A SysOps administrator is planning for disaster recovery of an RDS MySQL database. The database is currently in a single AZ. Which TWO actions will improve recovery time and reduce data loss? (Select TWO.)

Accepted Answer

Enable automated backups with a retention period of 7 days.. Enabling automated backups with a 7-day retention period allows point-in-time recovery (PITR) to any second within the retention window, minimizing data loss (RPO) by restoring to the most recent backup. Option C is correct because Multi-AZ deployment provides automatic synchronous standby replication to a different Availability Zone, enabling automatic failover with minimal downtime (RTO) in case of an AZ failure or instance issue.

Answer

Create a read replica in a different AWS Region.

Answer

Enable deletion protection on the RDS instance.

Answer

Increase the allocated storage to improve performance.

Question 11

A company runs a critical web application on EC2 instances behind an Application Load Balancer across three Availability Zones. The application stores session data in an RDS MySQL database. To improve reliability, the company wants to ensure that a single Availability Zone failure does not impact the application's availability. Which combination of actions should the SysOps administrator take?

Accepted Answer

Deploy RDS in Multi-AZ configuration with automatic failover, and enable cross-zone load balancing on the ALB.. Deploying RDS in Multi-AZ with automatic failover ensures database resilience against an AZ failure by maintaining a synchronous standby replica in a different AZ, while enabling cross-zone load balancing on the ALB distributes traffic across instances in all AZs, preventing a single AZ failure from taking down the entire application. Together, these actions address both the session data persistence and compute layer availability requirements.

Answer

Configure the ALB to use only healthy instances and enable detailed CloudWatch metrics.

Answer

Increase the EC2 instance size to handle more traffic in a single AZ.

Answer

Increase the Auto Scaling group's desired capacity to a larger number.

Question 12

A SysOps administrator is designing a backup strategy for an Amazon EFS file system. The file system stores critical data that must be recoverable within 15 minutes of a failure. Which solution meets these requirements?

Accepted Answer

Use AWS Backup to create automated backups of the EFS file system and restore to a new file system if needed.. AWS Backup provides a fully managed, policy-driven backup solution for Amazon EFS that supports automated, scheduled backups with point-in-time recovery. Restoring an EFS file system from a backup typically completes within minutes, meeting the 15-minute recovery time objective (RTO). This is the only option that directly addresses the requirement for recoverable backups with a defined RTO.

Answer

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

Answer

Take periodic EBS snapshots of the EC2 instance that mounts the EFS volume.

Answer

Create a Lambda function that copies files to an S3 bucket every hour.

Question 13

A SysOps administrator is troubleshooting an issue where an Auto Scaling group is not launching EC2 instances despite having a scaling policy that should trigger when CPU utilization exceeds 80%. The CloudWatch alarm shows that the metric is breaching the threshold, but no instances are launched. What is the most likely cause?

Accepted Answer

The Auto Scaling group has reached its maximum size.. When an Auto Scaling group reaches its maximum size, it cannot launch new instances even if a scaling policy is triggered. The CloudWatch alarm breaching the threshold indicates the scaling condition is met, but the group's capacity limit prevents any new instance launches. This is a common misconfiguration where the max size is set too low relative to the desired or current capacity.

Answer

The scaling policy is incorrectly configured to use a simple scaling policy instead of a step scaling policy.

Answer

The health check grace period is too long.

Answer

The CloudWatch alarm is in insufficient data state.

Question 14

A company is using Amazon S3 to store critical data with versioning enabled. The SysOps administrator needs to implement a solution that automatically transitions objects to S3 Glacier Deep Archive after 90 days and permanently deletes them after 7 years. Which S3 feature should be used?

Accepted Answer

S3 Lifecycle policies. S3 Lifecycle policies are the correct choice because they allow you to define rules that automatically transition objects to S3 Glacier Deep Archive after a specified number of days (90) and then permanently expire (delete) them after a longer period (7 years). This directly meets the requirements for automated, time-based storage class transitions and deletion without manual intervention.

Answer

S3 Intelligent-Tiering

Answer

S3 Object Lock

Answer

S3 Cross-Region Replication

Question 15

A company runs a stateful web application on EC2 instances behind a Network Load Balancer. The application requires that client requests from a particular session are always sent to the same target instance. Which feature should the SysOps administrator configure on the NLB to meet this requirement?

Accepted Answer

Configure sticky sessions using flow-based routing (client IP affinity). Network Load Balancers (NLBs) support session stickiness through flow-based routing based on the client's IP address and port (Layer 4). This ensures that requests from the same client session are consistently routed to the same target instance, meeting the requirement without using application-layer cookies.

Answer

Configure path-based routing rules

Answer

Enable health checks on the target group

Answer

Enable cross-zone load balancing