SOA-C03 Online Practice Questions

Explanation:
Tagging is essential for governance, cost management, and automation in CloudOps operations. The AWS Organizations tag policies feature allows centralized definition and enforcement of required tag keys and accepted values across all accounts in an organization. According to the AWS CloudOps study guide under Deployment, Provisioning, and Automation, tag policies enable automatic validation of tags, ensuring consistency with minimal manual overhead.
Once tagging consistency is enforced, enabling cost allocation tags in the AWS Billing and Cost Management console allows accurate cost distribution per business unit. AWS documentation states:
“Use AWS Organizations tag policies to standardize tags across accounts. You can activate cost allocation tags in the Billing console to track and allocate costs.”
Option B introduces unnecessary complexity with Lambda automation.
Option C detects but does not enforce tagging.
Option D limits flexibility to Service Catalog resources only. Therefore, Option A provides a centrally managed, automated, and low-overhead solution that meets CloudOps tagging and cost-tracking requirements.
Reference:
• AWS Certified CloudOps Engineer C Associate (SOA-C03) Exam Guide C Domain 3: Deployment, Provisioning and Automation
• AWS Organizations C Tag Policies
• AWS Billing and Cost Management C Cost Allocation Tags
• AWS Well-Architected Framework C Operational Excellence and Cost Optimization Pillars

Explanation:
According to the AWS Cloud Operations and Cost Management documentation, AWS Budgets is the recommended service to track and alert on cost thresholds across all AWS accounts and resources. It allows users to define cost, usage, or reservation budgets, and configure notifications to trigger when usage or cost reaches defined percentages of the budgeted value (e.g., 75%, 90%, 100%).
The AWS Budgets system integrates natively with Amazon Simple Notification Service (SNS) to deliver alerts to an email distribution list or SNS topic subscribers. AWS Budgets supports granular cost filters, including specific service categories such as data transfer, regions, or linked accounts, ensuring precise visibility into inter-Region transfer costs.
By contrast, CloudWatch billing alarms (Option B) monitor total account charges only and do not allow detailed service-level filtering, such as data transfer between Regions. Cost and Usage Reports (Option A) are for detailed cost analysis, not real-time alerting, and VPC Flow Logs (Option D) capture traffic data, not billing or cost-based metrics.
Thus, using AWS Budgets with a 75% alert threshold best satisfies the operational and notification requirements.
Reference: AWS CloudOps and Cost Management Guide C Section: AWS Budgets for Cost Monitoring and Alerts

Explanation:
The AWS Cloud Operations and Compute documentation explains that placement groups control how EC2 instances are physically arranged within AWS data centers to optimize network performance.
Among the available placement strategies:
Cluster placement groups place instances physically close together within a single Availability Zone, connected through high-bandwidth, low-latency networking (ideal for tightly coupled, HPC, or distributed workloads).
Spread placement groups distribute instances across distinct racks or Availability Zones for fault tolerance, increasing latency.
Partition placement groups separate instances into partitions for isolation, not latency reduction.
Therefore, to minimize latency for workloads such as computational clusters, the CloudOps engineer should use a cluster placement group. This placement ensures single-digit microsecond latency and enhanced packet rate performance between instances.
Elastic IPs (Option B) do not influence internal networking. Jumbo frames (Option C) can marginally improve throughput but do not reduce propagation latency. Spread placement (Option D) increases distance, worsening latency.
Hence, Option A ― using a cluster placement group ― delivers the lowest possible network latency and is AWS’s best-practice design for HPC-style clusters.
Reference: AWS Cloud Operations & Compute Optimization Guide C Optimizing EC2 Networking with Cluster Placement Groups for Low Latency Workloads

Explanation:
The PrivateDnsName attribute of an EC2 instance is automatically assigned by AWS at launch time and is a read-only property. CloudFormation does not allow users to specify this value manually.
Including PrivateDnsName in the EC2 instance properties causes validation to fail during stack creation. Outputs and Parameters sections are optional, and the VPC is implicitly defined through the subnet ID.
Therefore, attempting to set PrivateDnsName results in stack creation failure.

Explanation:
The combination of geoproximity routing and DNS failover health checks provides global low-latency routing with high availability.
Geoproximity routing in Route 53 routes users to the AWS Region closest to their geographic location, optimizing latency. For automatic failover, Route 53 health checks can monitor CloudWatch alarms tied to the health of the ALB in each Region. When a Region becomes unhealthy, Route 53 reroutes traffic to the next available Region automatically.
AWS documentation states:
“Use geoproximity routing to direct users to resources based on geographic location, and configure health checks to provide DNS failover for high availability.”
Option B incorrectly monitors EC2 instances directly, which is not efficient at scale.
Option C uses private IPs, which cannot be globally health-checked.
Option E (simple routing) does not support geographic or failover routing. Hence, A and D together meet both the proximity and failover requirements.
Reference:
• AWS Certified CloudOps Engineer C Associate (SOA-C03) Exam Guide C Domain 5: Networking and Content Delivery
• Amazon Route 53 Developer Guide C Geoproximity Routing and DNS Failover
• AWS Well-Architected Framework C Reliability Pillar
• Amazon CloudWatch Alarms C Integration with Route 53 Health Checks