SOA-C02 Practice Exam 61 — 20 Questions

Question 1

A company wants to monitor the performance of its Amazon RDS for MySQL database. The database is experiencing high CPU utilization during peak hours. The SysOps administrator needs to identify the queries causing the load. Which AWS service should be used?

Accepted Answer

Amazon RDS Performance Insights. Option C is correct because Amazon RDS Performance Insights provides a dashboard that visualizes database load and helps identify the queries that are causing high CPU usage. Option A is wrong because Amazon CloudWatch Logs only collects log files, not query performance data. Option B is wrong because AWS CloudTrail records API activity, not database queries. Option D is wrong because Amazon Inspector is a vulnerability management service, not a database performance tool.

Answer

AWS CloudTrail

Answer

Amazon Inspector

Answer

Amazon CloudWatch Logs

Question 2

A SysOps administrator notices that an Amazon RDS for MySQL instance has high read activity. The application performs many read queries but few writes. The database is currently a single db.r5.large instance. What change would improve read performance and reduce cost?

Accepted Answer

Create a read replica and use a smaller instance type for the replica.. Adding a read replica distributes read traffic, improving performance, and using a smaller instance type for the replica reduces cost. Option A is wrong because vertical scaling increases cost. Option B is wrong because Multi-AZ does not offload reads. Option D is wrong because moving to DynamoDB may not be compatible with the application.

Answer

Enable Multi-AZ for high availability and use the standby for reads.

Answer

Increase the instance size to db.r5.xlarge.

Answer

Migrate the database to Amazon DynamoDB.

Question 3

A SysOps administrator notices that an S3 bucket's storage costs have increased significantly. The bucket stores log files and is configured with S3 Standard storage class. Most logs are accessed only once after 30 days. Which action will reduce costs without affecting data retrieval?

Accepted Answer

Create a lifecycle policy to transition objects to S3 Glacier Instant Retrieval after 30 days.. Option C is correct because transitioning to S3 Glacier Instant Retrieval after 30 days reduces storage cost while maintaining millisecond access. Option A is wrong because S3 Standard-IA has retrieval fees that might increase cost for single access. Option B is wrong because S3 One Zone-IA is cheaper but less durable. Option D is wrong because S3 Glacier Deep Archive has long retrieval times.

Answer

Create a lifecycle policy to transition objects to S3 Standard-IA after 30 days.

Answer

Create a lifecycle policy to transition objects to S3 Glacier Deep Archive after 30 days.

Answer

Create a lifecycle policy to transition objects to S3 One Zone-IA after 30 days.

Question 4

A company wants to monitor the performance of its application running on EC2. Which TWO metrics should be monitored to detect performance bottlenecks? (Choose TWO.)

Accepted Answer

CPU Utilization. Options A and C are correct. CPU utilization (A) and Memory utilization (C) are key performance metrics. Option B is wrong because Disk space is not a metric by default; it requires custom scripts. Option D is wrong because Network packets in is not a standard performance metric. Option E is wrong because Status check is for health, not performance.

Answer

Network Packets In

Answer

Status Check Failed

Answer

Disk Space Utilization

Question 5

A company wants to optimize costs for its Amazon EC2 instances. Which TWO strategies are effective for reducing costs?

Accepted Answer

Use Spot Instances for fault-tolerant workloads.. Using Spot Instances for fault-tolerant workloads can reduce costs significantly (up to 90%). Rightsizing instances ensures you are not paying for unused capacity. Dedicated Hosts increase costs. Increasing provisioned IOPS increases costs. Using EBS General Purpose SSD (gp3) is cost-effective but not a primary cost reduction strategy.

Answer

Increase the provisioned IOPS for EBS volumes.

Answer

Use EBS General Purpose SSD (gp2) volumes instead of gp3.

Answer

Use Dedicated Hosts to meet compliance requirements.

Question 6

A company is using Amazon EBS volumes for a high-performance database. The volumes are gp2 type. The database workload is write-intensive, and the company is experiencing high costs due to provisioned IOPS. The database team wants to maintain performance while reducing costs. Which EBS volume type should the company use?

Accepted Answer

gp3. gp3 volumes provide baseline performance independent of volume size, and customers pay only for provisioned IOPS above baseline, offering cost savings for write-intensive workloads. Option A is wrong because io2 volumes are more expensive. Option B is wrong because st1 is not suitable for database workloads. Option D is wrong because sc1 is lowest cost but poor performance.

Answer

sc1 (Cold HDD)

Answer

st1 (Throughput Optimized HDD)

Answer

io2 Block Express

Question 7

A company wants to monitor the performance of its EC2 instances and receive alerts when CPU utilization exceeds 80% for 10 minutes. Which AWS service should be used?

Accepted Answer

Amazon CloudWatch. Option B is correct because CloudWatch can monitor EC2 metrics and trigger alarms. Option A is wrong because AWS Config is for configuration auditing. Option C is wrong because CloudTrail is for API logging. Option D is wrong because VPC Flow Logs capture network traffic.

Answer

AWS CloudTrail

Answer

AWS Config

Answer

VPC Flow Logs

Question 8

A company runs a production database on an Amazon RDS for PostgreSQL instance. The company notices that the database is experiencing high CPU utilization during peak hours, causing performance degradation. The company wants to improve performance while minimizing cost. Which solution should the company implement?

Accepted Answer

Add an Amazon RDS read replica to offload read traffic.. Adding a read replica offloads read traffic from the primary instance, reducing CPU utilization. Read replicas are cost-effective and can be promoted if needed. Scaling up the instance type increases cost and may not be necessary. Multi-AZ provides high availability but does not reduce CPU load. ElastiCache would require application changes and adds cost.

Answer

Create a Multi-AZ deployment for high availability.

Answer

Implement Amazon ElastiCache in front of the database.

Answer

Scale up the DB instance class to a larger size.

Question 9

An administrator attaches the above IAM policy to a user. The user needs to stop an EC2 instance to save costs. The user reports that they are unable to stop the instance. What is the MOST likely cause?

Accepted Answer

The instance is part of an Auto Scaling group.. The policy allows ec2:StopInstances but the Deny statement for ec2:TerminateInstances might not affect stopping. However, the issue could be that the user does not have permissions to describe instances if the resource is not specified correctly. But the policy has Allow for DescribeInstances on all resources. The problem might be that the instance has termination protection enabled. IAM policy does not explicitly deny stop, so the Deny on terminate should not affect stop. Termination protection prevents both stop and terminate if it is configured to protect against accidental termination, but stop is not prevented unless specified. Actually, termination protection only protects against termination, not stop. The most likely cause is that the instance has termination protection enabled, but that does not prevent stop. Alternatively, the user might not have the ec2:StopInstances permission if there is an implicit deny? But the policy explicitly allows it. The answer is that the instance has termination protection enabled, but that is incorrect for stop. Another possibility: the user's session may not have the necessary permissions due to a service control policy (SCP) or resource-based policy. However, based on the policy, the user should be able to stop. The exhibit shows a Deny for TerminateInstances, which does not affect StopInstances. So the issue might be that the instance is part of an Auto Scaling group and has a scale-in protection? That would prevent termination but not stop. The correct answer is that the instance has termination protection enabled, which does not prevent stop. I need to think differently. Perhaps the user is trying to stop a stopped instance? Or the instance is an EBS-backed instance, and stopping is allowed. The most common reason for inability to stop is that the instance is part of an Auto Scaling group and the user does not have permission to modify the Auto Scaling group? But the policy does not include Auto Scaling actions. The answer might be that the instance has termination protection enabled, but that is not correct. Let me re-evaluate: The policy allows StopInstances, so the user should be able to stop. The only Deny is on TerminateInstances. So why can't they stop? Possibly because the instance is in a running state and there is a conflict with another policy? The most likely cause from the options is that the instance has termination protection enabled, but that is a distractor. Actually, termination protection does not prevent stop. So the correct answer should be that the user does not have permission to stop because the policy does not include the ec2:StopInstances action? But it does. I'm confused. Let me check AWS documentation: Termination protection prevents termination, not stop. So the user should be able to stop. Perhaps the issue is that the instance is an instance store-backed instance, which cannot be stopped? But the exhibit does not indicate that. I think the correct answer is that the instance has termination protection enabled, but that is wrong. Maybe the answer is that the IAM policy has a Deny on TerminateInstances which also affects StopInstances? No. Let me look at the options: A. The IAM policy does not allow StopInstances. B. The instance has termination protection enabled. C. The instance is part of an Auto Scaling group. D. The user does not have permission to describe instances. Option A is false because the policy explicitly allows StopInstances. Option B is plausible but termination protection does not block stop. Option C could be true if the Auto Scaling group has a scale-in protection but that also does not block stop. Option D is false because DescribeInstances is allowed. So what is correct? I recall that if an instance is part of an Auto Scaling group, you cannot stop it directly because the Auto Scaling group will automatically restart it. But the question says "unable to stop the instance" which might be due to the Auto Scaling group maintaining the desired count. However, the user can still stop the instance, but the Auto Scaling group will immediately start a new one. So the stop action would succeed, but the user might think it didn't because a new instance appears. The question likely expects that the Auto Scaling group prevents stopping. Actually, you can stop an instance in an Auto Scaling group, but the Auto Scaling group will launch a new one, so the stop is not effective for cost saving. The user might be trying to stop to save costs, but if the instance is in an Auto Scaling group, stopping it will not save costs because the group will replace it. So the most likely cause is that the instance is part of an Auto Scaling group. I'll go with that.

Answer

The instance has termination protection enabled.

Answer

The IAM policy does not allow ec2:StopInstances.

Answer

The user does not have permission to describe instances.

Question 10

An application running on Amazon EC2 generates a large number of small files that are stored temporarily and deleted after 24 hours. The files are accessed frequently within the first hour and then rarely. Which Amazon S3 storage class is MOST cost-effective for this use case?

Accepted Answer

S3 Intelligent-Tiering. S3 Intelligent-Tiering automatically moves objects between tiers based on access patterns, making it cost-effective for unpredictable access. Option A is wrong because S3 Standard is more expensive for rarely accessed data. Option B is wrong because S3 One Zone-IA may have lower durability but not necessarily lower cost for this pattern. Option D is wrong because S3 Glacier Deep Archive has a minimum storage duration of 180 days.

Answer

S3 Glacier Deep Archive

Answer

S3 One Zone-Infrequent Access

Answer

S3 Standard

Question 11

A company runs a web application on EC2 instances behind an Application Load Balancer. The application experiences variable traffic patterns. The operations team notices that during low traffic periods, there are still a large number of running instances, leading to higher costs. What should the team do to reduce costs while maintaining performance?

Accepted Answer

Implement a target tracking scaling policy based on average CPU utilization.. Using a target tracking scaling policy based on average CPU utilization allows the Auto Scaling group to automatically adjust the number of instances based on demand, reducing costs during low traffic. Option A is wrong because manual scaling does not automate cost optimization. Option B is wrong because Reserved Instances do not address variable traffic. Option D is wrong because increasing instance size may not reduce the number of instances during low traffic.

Answer

Replace the existing instances with larger instance types to handle peak load.

Answer

Manually scale down the number of instances during off-peak hours.

Answer

Purchase Reserved Instances for the baseline capacity.

Question 12

A SysOps administrator wants to receive alerts when the estimated charges for an AWS account exceed a certain threshold. Which AWS service should be used?

Accepted Answer

AWS Budgets. AWS Budgets allows you to set cost budgets and receive alerts when actual or forecasted costs exceed thresholds. Option A is wrong because CloudWatch metrics for billing are available, but alerts are set via Budgets. Option B is wrong because Cost Explorer does not send alerts. Option D is wrong because Trusted Advisor provides cost optimization recommendations but not budget alerts.

Answer

AWS Trusted Advisor

Answer

AWS Cost Explorer

Answer

Amazon CloudWatch (billing metric)

Question 13

A company stores infrequently accessed data in S3 Standard. They want to reduce storage costs without compromising immediate accessibility. What is the MOST cost-effective solution?

Accepted Answer

Use S3 Standard-IA storage class.. Option C is correct because S3 Standard-IA offers lower storage cost with immediate access, for infrequently accessed data. Option A is wrong because S3 Intelligent-Tiering has monitoring costs. Option B is wrong because lifecycle policies are used to transition, not a storage class. Option D is wrong because S3 Glacier Flexible Retrieval has minutes to hours retrieval.

Answer

Use S3 Glacier Flexible Retrieval.

Answer

Move data to S3 Intelligent-Tiering.

Answer

Create a lifecycle policy to delete objects after 30 days.

Question 14

A company uses Amazon CloudWatch to monitor its AWS resources. The company wants to receive alerts when CPU utilization of an EC2 instance exceeds 80% for 5 consecutive minutes. What is the MOST efficient way to achieve this?

Accepted Answer

Create a CloudWatch alarm on the CPUUtilization metric with a threshold of 80% for 5 consecutive periods.. A CloudWatch alarm can be set to trigger when the CPUUtilization metric exceeds 80% for 5 consecutive minutes (e.g., 5 evaluation periods of 1 minute each). This is the native and efficient way. CloudWatch Logs is for log data. CloudTrail is for API activity. EventBridge is for event-driven actions but requires a more complex setup.

Answer

Use CloudWatch Logs to parse CPU utilization from system logs and trigger an alert.

Answer

Use Amazon EventBridge to schedule a Lambda function that checks CPU utilization.

Answer

Use AWS CloudTrail to monitor EC2 instance metrics.

Question 15

An administrator runs the above CloudWatch command to analyze CPU utilization for an EC2 instance. The instance is currently running with a t3.large instance type. The company wants to optimize costs. Based on the data, which action should the administrator take?

Accepted Answer

Downsize the instance to t3.medium to reduce costs.. The average CPU utilization over the week is low (around 15.5%), indicating the instance is over-provisioned. Downsizing to a t3.medium (half the vCPUs and memory) would likely be sufficient and reduce costs. Reserved Instances would be cost-effective only if the instance runs consistently, but the current utilization is low. Scaling up would increase costs. Stopping the instance is not an option if needed.

Answer

Stop the instance to save costs immediately.

Answer

Scale up the instance to t3.xlarge to improve performance.

Answer

Purchase a Reserved Instance for the current instance type.

Question 16

Which TWO AWS services can be used to monitor the performance of an EC2 instance?

Accepted Answer

AWS Systems Manager. Options B and D are correct. CloudWatch provides metrics like CPU utilization. Systems Manager can collect performance data via Inventory and Run Command. AWS Config tracks configuration, not performance. Trusted Advisor gives recommendations. CloudTrail is for API activity.

Answer

AWS CloudTrail

Answer

AWS Trusted Advisor

Answer

AWS Config

Question 17

A SysOps administrator is troubleshooting slow application performance. The application runs on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer. Amazon CloudWatch metrics show that the average CPU utilization across the instances is below 20%, but the application is still slow. What is the MOST likely cause of the performance issue?

Accepted Answer

The application database is under-provisioned and is causing slow query responses.. Option B is correct because if the database is the bottleneck, even if the application servers have low CPU usage, the overall performance can be slow due to database contention. Option A is wrong because if the ALB is not distributing traffic, some instances would have high CPU. Option C is wrong because low CPU utilization indicates that the application servers are not overloaded. Option D is wrong because burstable performance instances (T-series) have a CPU credit balance; if the balance is depleted, CPU performance is throttled, leading to low CPU but slow performance? Actually, when credits are exhausted, T instances provide baseline performance, which may be low, but CPU utilization would still be limited, not necessarily low; but more importantly, the symptoms match a database bottleneck.

Answer

The Auto Scaling group is scaling too aggressively, causing thrashing.

Answer

The Application Load Balancer has a sticky session configuration that is not distributing traffic evenly.

Answer

The EC2 instances are using burstable performance and have exhausted their CPU credits.

Question 18

A company has a data processing job that runs on Amazon EMR. The job takes 2 hours to complete and runs once per day. The SysOps administrator wants to reduce costs without affecting the completion time. Which strategy is MOST effective?

Accepted Answer

Use Spot Instances for the task nodes in the EMR cluster.. Option D is correct because using Spot Instances for task nodes (which are fault-tolerant) can significantly reduce costs, as Spot Instances are often 60-80% cheaper than On-Demand. The job's duration is predictable, and if a Spot Instance is interrupted, EMR can relaunch the task on another instance. Option A is wrong because using a smaller number of larger instances may not reduce costs; in fact, it could increase costs if the job requires parallel processing. Option B is wrong because reducing the number of instances will increase the job duration. Option C is wrong because EMR does not support Savings Plans directly for the EMR service itself; Savings Plans cover EC2 instances used by EMR, but the same savings can be achieved with Spot.

Answer

Use a smaller number of larger EC2 instances.

Answer

Reduce the number of core nodes.

Answer

Purchase Compute Savings Plans for the EMR cluster.

Question 19

A SysOps administrator is managing a fleet of Amazon EC2 instances that run a batch processing job. The job runs for 30 minutes every hour. The administrator wants to optimize costs by using Spot Instances but must ensure that the job completes even if Spot Instances are interrupted. Which configuration should the administrator use?

Accepted Answer

Use a mixed instances policy with both On-Demand and Spot Instances, and configure the Spot allocation strategy to 'lowestPrice'.. Option B is correct because using a mixed instances policy with both On-Demand and Spot Instances ensures that the baseline capacity is covered by On-Demand, and any interrupted Spot Instances can be replaced by On-Demand as a fallback. The Spot allocation strategy 'lowestPrice' is not specified but the key is the capacity-optimized or diversified strategy to reduce interruption. However, the question asks for ensuring completion; the best practice is to use a capacity-optimized allocation strategy. Actually, the correct answer is B: Use a mixed instances policy with a capacity-optimized allocation strategy and specify a percentage of On-Demand instances. But option B says 'lowestPrice', which is common but not best for stability. However, among the options, B is the only one that includes a mix. Option A is wrong because only Spot is risky. Option C is wrong because the job is not long-running (30 min), so persistence is not needed; but the job must complete, so if Spot is interrupted, it should be able to restart. Option D is wrong because it is wasteful to use only On-Demand.

Answer

Launch Spot Instances in an Auto Scaling group with a capacity-optimized allocation strategy.

Answer

Use a Spot Fleet with a 'persistent' request type.

Answer

Use only On-Demand Instances to avoid interruptions.

Question 20

A company wants to reduce costs for a production Amazon RDS for MySQL DB instance that is running 24/7 but only heavily used during business hours (9 AM to 5 PM). Which TWO actions would be MOST effective in optimizing costs without significantly impacting performance during peak hours?

Accepted Answer

Purchase Reserved Instances for the DB instance.. Option A (Multi-AZ) increases cost and is not needed for cost optimization. Option B (reserved instances) provides a discount for consistent usage. Option C (auto scaling) is not applicable to RDS without additional services like Aurora Auto Scaling. Option D (scheduled scaling) can reduce instance size during off-peak hours, saving cost. Option E (gp3 storage) can be more cost-effective than provisioned IOPS for many workloads. Correct answers: B and D.

Answer

Enable Multi-AZ deployment for high availability.

Answer

Migrate from Provisioned IOPS (io1) storage to General Purpose (gp3) storage.

Answer

Enable Auto Scaling for the DB instance.