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

Question 1

A SysOps administrator needs to implement a backup strategy for an Amazon RDS for PostgreSQL database. The database is 500 GB and experiences heavy write traffic. Which solution provides the most cost-effective backup with the least impact on database performance?

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

Accepted Answer

Enable automated backups with a retention period of 7 days.. Automated backups are enabled by default with minimal performance impact and include transaction logs for point-in-time recovery. Option B is wrong; while using a standby for backups in Multi-AZ can reduce impact, automated backups already have minimal impact and are more cost-effective. Option C is wrong because AWS DMS replication to S3 is not a backup solution and adds complexity and cost. Option D is wrong because manual snapshots cause a brief I/O suspension and are less automated than automated backups.

Answer

Create a Multi-AZ deployment and use the standby for backups.

Answer

Use AWS Database Migration Service to continuously replicate data to an S3 bucket.

Answer

Take manual DB snapshots daily during off-peak hours.

Question 2

A company runs a stateful web application on EC2 instances in an Auto Scaling group behind an Application Load Balancer. Users report that their sessions are frequently lost during scaling events. What is the MOST effective solution to maintain session persistence?

Accepted Answer

Modify the application to store session data in an external data store such as ElastiCache or DynamoDB.. Externalizing session state to a durable, shared data store like ElastiCache or DynamoDB decouples session data from individual EC2 instances. This ensures that sessions survive scaling events, including instance termination during scale-in, because any instance can retrieve the session from the external store. Sticky sessions (option C) only route traffic to the same instance, but they do not preserve session data if that instance is terminated. Options A and D do not address session persistence at all.

Answer

Increase the cooldown period for the Auto Scaling group.

Answer

Enable sticky sessions (session affinity) on the Application Load Balancer.

Answer

Use larger EC2 instance types to reduce the frequency of scaling.

Question 3

A company has an S3 bucket that stores critical financial data. The bucket versioning is enabled. A SysOps administrator needs to ensure that data can be recovered after accidental deletion by users. What is the MOST effective way to protect against accidental deletion?

Accepted Answer

Enable MFA Delete on the S3 bucket.. MFA Delete is the most effective protection against accidental deletion because it requires multi-factor authentication (a second factor) to permanently delete objects or suspend versioning. This prevents even authorized users from accidentally deleting objects. Option A is incorrect because lifecycle policies manage storage tiers, not deletion prevention. Option B is too restrictive: denying all s3:DeleteObject would block legitimate deletions and may not be practical. Option C (cross-region replication) provides disaster recovery but does not prevent deletion in the source bucket; replicated objects could also be deleted.

Answer

Configure a lifecycle policy to transition objects to Glacier after 30 days.

Answer

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

Answer

Replicate objects to another S3 bucket in a different AWS Region.

Question 4

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.. When Multi-AZ failover occurs, RDS updates the DNS CNAME record to point to the new primary instance in a different Availability Zone. If the application uses the IP address directly instead of the DNS endpoint, it will continue to resolve to the old (now failed) instance's IP, which is no longer accessible. The DNS endpoint is the only stable reference that automatically follows the failover.

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 5

A company runs a critical application on an EC2 instance that stores data on an EBS volume. The SysOps administrator needs to implement a backup strategy that provides the ability to restore the volume to a specific point in time within the last 24 hours, with a recovery time objective (RTO) of less than 15 minutes. Which solution meets these requirements?

Accepted Answer

Schedule EBS snapshots every hour and keep them for 24 hours.. Scheduling EBS snapshots every hour and retaining them for 24 hours provides point-in-time recovery granularity within the last 24 hours. EBS snapshots are incremental, stored in Amazon S3, and can be used to create a new volume or restore an existing one; restoring from a snapshot typically takes only a few minutes, meeting the RTO of less than 15 minutes.

Answer

Configure a RAID 1 mirror of the EBS volume across two Availability Zones.

Answer

Enable automated backups on the EC2 instance.

Answer

Use AWS Backup to create backup plans for the EBS volume.

Question 6

A company has a fleet of EC2 instances that need to be patched monthly. The SysOps administrator must ensure that the patching process does not affect the availability of the application. Which strategy should the administrator use?

Accepted Answer

Use an Auto Scaling group with a rolling update strategy.. Using an Auto Scaling group with a rolling update strategy allows the administrator to replace instances in batches, ensuring that a minimum number of instances remain in service throughout the patching process. This maintains application availability by avoiding simultaneous disruption to all instances, which is a key requirement for high-availability architectures.

Answer

Patch one instance at a time manually by stopping and starting.

Answer

Use AWS Systems Manager Patch Manager to patch all instances at once.

Answer

Stop all instances, apply patches, then start them.

Question 7

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.. The application stores session data locally on each EC2 instance, so when new instances are launched during a traffic spike, the load balancer may route a user's subsequent request to a different instance that does not have their session data, causing them to be logged out. Enabling sticky sessions (session affinity) on the Application Load Balancer ensures that all requests from a user during a session are sent to the same instance, preserving the locally stored session data without requiring any application modifications.

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 8

A company uses Amazon S3 to store backup data. The SysOps administrator needs to ensure that the data is protected against accidental deletion by users with administrative privileges. Which combination of actions should the administrator take? (Choose TWO.)

Accepted Answer

Enable MFA Delete on the S3 bucket.. Options A and C are correct because enabling MFA Delete requires multi-factor authentication for delete operations, adding protection against accidental or malicious deletions, and enabling versioning allows recovery of deleted or overwritten objects by restoring previous versions. Option B is incorrect because a bucket policy that denies s3:DeleteObject to all users would prevent any deletion, including legitimate ones, and does not target accidental deletions specifically. Option D is incorrect because a lifecycle policy to transition objects to Amazon S3 Glacier only changes the storage class, offering no protection against deletion. Option E is incorrect because AWS CloudTrail provides auditing of API calls but does not prevent deletion.

Answer

Apply an S3 bucket policy that denies s3:DeleteObject for all users.

Answer

Configure a lifecycle policy to transition objects to S3 Glacier.

Answer

Enable AWS CloudTrail to log all S3 API calls.

Question 9

A company is designing a disaster recovery strategy for a production RDS for MySQL database. The database is currently single-AZ. The recovery point objective (RPO) is 1 hour, and the recovery time objective (RTO) is 15 minutes. Which steps should the SysOps administrator take to meet these requirements? (Choose THREE.)

Accepted Answer

Take manual DB snapshots every hour.. Manual DB snapshots can be taken on demand, and taking them every hour ensures that the recovery point objective (RPO) of 1 hour is met. In the event of a failure, you can restore the database from the latest manual snapshot, which provides a point-in-time recovery point within the RPO window. However, manual snapshots alone do not meet the 15-minute recovery time objective (RTO), so they must be combined with other measures like Multi-AZ and automated backups.

Answer

Disable automated backups to reduce performance impact.

Answer

Create a read replica in a different Availability Zone.

Question 10

A company runs a stateless web application on EC2 instances behind an Application Load Balancer. The application is deployed in an Auto Scaling group with a minimum of 2 and maximum of 10 instances. During a traffic spike, the Auto Scaling group launches new instances, but the new instances are immediately marked as unhealthy by the ALB and terminated. What could be the cause? (Choose TWO.)

Accepted Answer

The health check path is misconfigured.. The ALB uses the configured health check path to determine instance health. If the path (e.g., /health) does not return a 200 OK response from the application on new instances, the ALB marks them as unhealthy and deregisters them. This is a common misconfiguration when the health check endpoint is not properly implemented or the path is incorrect.

Answer

The Auto Scaling group does not have sufficient capacity in the target AZ.

Answer

The instances do not have the required IAM role to register with the ALB.

Answer

The instances are launched with a larger instance type than expected.

Question 11

Refer to the exhibit. A SysOps administrator ran the commands shown. What is the state of the EC2 instance?

Accepted Answer

The instance is running but has a system impairment.. The `aws ec2 describe-instance-status` command with the `--instance-id` flag returns the instance's system status checks. The output shows `SystemStatus: impaired`, which indicates that the instance is running but has a system impairment (e.g., loss of network connectivity or power). This status is determined by AWS's automated status checks that run every minute, and an impaired status means the underlying host has an issue that affects the instance.

Answer

The instance is running and healthy.

Answer

The instance is terminated.

Answer

The instance is stopped.

Question 12

Refer to the exhibit. A SysOps administrator deployed the CloudFormation template. Which statement is true about data protection?

Accepted Answer

Deleted objects become noncurrent versions and are retained for 30 days.. The CloudFormation template likely configures an S3 bucket with versioning enabled and a lifecycle policy that transitions noncurrent versions to the 'ExpiredObjectDeleteMarker' or retains them for a specified period. By default, when versioning is enabled, deleted objects are not permanently removed but become noncurrent versions, and the lifecycle rule can be set to permanently delete these noncurrent versions after 30 days, as indicated in the template.

Answer

Deleted objects are immediately and permanently removed.

Answer

The bucket cannot be deleted by anyone.

Answer

Objects cannot be deleted from the bucket.

Question 13

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.. Storing session data on local instance storage is ephemeral; if an instance is terminated or replaced during scaling events, session data is lost, causing users to be logged out. Moving session state to an external, highly available service like ElastiCache Redis ensures persistence across instance lifecycles and improves reliability under peak traffic.

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 14

A company uses AWS CloudFormation to deploy infrastructure. They want to ensure that if a stack update fails, the stack automatically rolls back to the last known good state. Which CloudFormation stack policy should be used?

Accepted Answer

Use the default 'Rollback on failure' setting.. The default 'Rollback on failure' setting in AWS CloudFormation automatically triggers a stack rollback to the last known good state when a stack update fails. This is the built-in behavior that ensures reliability by reverting changes if an error occurs during the update process.

Answer

Enable termination protection on the stack.

Answer

Use a stack policy that prevents specific resources from being updated.

Answer

Set 'DisableRollback' to false.

Question 15

A company uses Amazon S3 to store critical data. They need to protect against accidental deletion of objects. Which feature should the SysOps Administrator enable?

Accepted Answer

Enable versioning on the bucket.. Enabling S3 Versioning preserves every version of an object, including overwrites and deletes. When versioning is enabled, a DELETE request does not remove the object permanently; instead, it adds a delete marker, allowing the object to be restored by removing the marker. This directly protects against accidental deletion by providing a recoverable history of all object changes.

Answer

Create a lifecycle policy to transition objects to Glacier.

Answer

Configure cross-region replication.

Answer

Enable MFA Delete on the bucket.