Question.41 A DevOps engineer is building a multistage pipeline with AWS CodePipeline to build, verify, stage, test, and deploy an application. A manual approval stage is required between the test stage and the deploy stage. The development team uses a custom chat tool with webhook support that requires near-real-time notifications. How should the DevOps engineer configure status updates for pipeline activity and approval requests to post to the chat tool? (A) Create an Amazon CloudWatch Logs subscription that filters on CodePipeline Pipeline Execution State Change. Publish subscription events to an Amazon Simple Notification Service (Amazon SNS) topic. Subscribe the chat webhook URL to the SNS topic, and complete the subscription validation. (B) Create an AWS Lambda function that is invoked by AWS CloudTrail events. When a CodePipeline Pipeline Execution State Change event is detected, send the event details to the chat webhook URL. (C) Create an Amazon EventBridge rule that filters on CodePipeline Pipeline Execution State Change. Publish the events to an Amazon Simple Notification Service (Amazon SNS) topic. Create an AWS Lambda function that sends event details to the chat webhook URL. Subscribe the function to the SNS topic. (D) Modify the pipeline code to send the event details to the chat webhook URL at the end of each stage. Parameterize the URL so that each pipeline can send to a different URL based on the pipeline environment. |
41. Click here to View Answer
Answer: C
Explanation:
The correct answer is C. Here’s a detailed justification:
D: Modifying the pipeline code directly is not a scalable or maintainable solution. It tightly couples the pipeline logic with the notification mechanism, making it harder to manage and update notifications for multiple pipelines or different chat tools. It also introduces redundancy by requiring modification of each pipeline.
Event-Driven Architecture: The scenario requires near real-time notifications, making an event-driven architecture the most suitable approach. AWS CodePipeline state changes are events that can trigger actions.
Amazon EventBridge: EventBridge is designed for routing events between AWS services and custom applications. It provides the necessary filtering capabilities to specifically target CodePipeline state change events. https://aws.amazon.com/eventbridge/
Filtering: EventBridge rules can filter events based on specific criteria, such as pipeline name, stage name, and state. This ensures that only relevant events (e.g., pipeline execution state changes, approval requests) trigger notifications.
Amazon SNS: SNS is a messaging service that enables decoupled communication between services. By publishing events to an SNS topic, multiple subscribers can receive notifications. https://aws.amazon.com/sns/
AWS Lambda for Transformation & Delivery: Directly publishing EventBridge events to a chat webhook might not be ideal due to formatting requirements. A Lambda function can subscribe to the SNS topic, receive the event details, transform the data into the format expected by the chat tool’s webhook, and then send the formatted message to the webhook URL. This provides flexibility in adapting the event data to the specific API of the chat tool. https://aws.amazon.com/lambda/
Near Real-Time: EventBridge, SNS, and Lambda work together to provide near real-time notifications as soon as a relevant pipeline event occurs.
Why other options are incorrect:
A: CloudWatch Logs are primarily for log data, not general event routing. While you can use CloudWatch Logs subscriptions to react to events, EventBridge is the dedicated service for event routing.
B: CloudTrail logs API calls and changes to resources. While it can be used for pipeline state changes, it’s less efficient and more resource-intensive than EventBridge for this specific purpose. CloudTrail is also not designed for near-real time.
Question.42 A company’s application development team uses Linux-based Amazon EC2 instances as bastion hosts. Inbound SSH access to the bastion hosts is restricted to specific IP addresses, as defined in the associated security groups. The company’s security team wants to receive a notification if the security group rules are modified to allow SSH access from any IP address. What should a DevOps engineer do to meet this requirement? (A) Create an Amazon EventBridge rule with a source of aws.cloudtrail and the event name AuthorizeSecurityGroupIngress. Define an Amazon Simple Notification Service (Amazon SNS) topic as the target. (B) Enable Amazon GuardDuty and check the findings for security groups in AWS Security Hub. Configure an Amazon EventBridge rule with a custom pattern that matches GuardDuty events with an output of NON_COMPLIANT. Define an Amazon Simple Notification Service (Amazon SNS) topic as the target. (C) Create an AWS Config rule by using the restricted-ssh managed rule to check whether security groups disallow unrestricted incoming SSH traffic. Configure automatic remediation to publish a message to an Amazon Simple Notification Service (Amazon SNS) topic. (D) Enable Amazon Inspector. Include the Common Vulnerabilities and Exposures-1.1 rules package to check the security groups that are associated with the bastion hosts. Configure Amazon Inspector to publish a message to an Amazon Simple Notification Service (Amazon SNS) topic. |
42. Click here to View Answer
Answer: A
Explanation:
The correct answer is A. Here’s why:
A. Create an Amazon EventBridge rule with a source of aws.cloudtrail and the event name AuthorizeSecurityGroupIngress. Define an Amazon Simple Notification Service (Amazon SNS) topic as the target.
This solution directly addresses the requirement of detecting modifications to security group rules that allow SSH access from any IP address.
- CloudTrail: AWS CloudTrail logs API calls made within your AWS account. Modifying security group rules triggers
AuthorizeSecurityGroupIngress
API calls. - EventBridge: EventBridge allows you to create rules that trigger actions based on specific events. In this case, the rule listens for the
AuthorizeSecurityGroupIngress
event from CloudTrail. - Filtering: The EventBridge rule can be configured to filter specifically for
AuthorizeSecurityGroupIngress
events that modify security group rules to allow SSH (port 22) from any IP address (0.0.0.0/0). This level of filtering is crucial to avoid unnecessary notifications for other security group changes. - SNS: Amazon SNS is a messaging service used to send notifications. The EventBridge rule is configured to send a notification to an SNS topic whenever a matching security group modification event occurs. Subscribers to this SNS topic (e.g., the security team) will receive the notification.
Why other options are not as suitable:
- B. Enable Amazon GuardDuty and check the findings for security groups in AWS Security Hub. Configure an Amazon EventBridge rule with a custom pattern that matches GuardDuty events with an output of NON_COMPLIANT. Define an Amazon Simple Notification Service (Amazon SNS) topic as the target. GuardDuty is primarily designed for threat detection and continuous security monitoring, rather than configuration change tracking. While GuardDuty might eventually detect this, the delay is unacceptable compared to immediately triggering off the event. Security Hub is a central console for security findings, not a system for direct notification.
- C. Create an AWS Config rule by using the restricted-ssh managed rule to check whether security groups disallow unrestricted incoming SSH traffic. Configure automatic remediation to publish a message to an Amazon Simple Notification Service (Amazon SNS) topic. AWS Config is valuable for compliance and configuration management. While it can detect deviations from desired configurations, the standard
restricted-ssh
rule is not triggered immediately upon a change; rather it runs periodic checks, which may delay the alert and not meet the requirements. Automatic remediation is overkill and may be undesirable; the requirement only specifies notification. - D. Enable Amazon Inspector. Include the Common Vulnerabilities and Exposures-1.1 rules package to check the security groups that are associated with the bastion hosts. Configure Amazon Inspector to publish a message to an Amazon Simple Notification Service (Amazon SNS) topic. Amazon Inspector focuses on vulnerability assessments of EC2 instances and container images, rather than configuration changes. It is less suitable for tracking security group modifications.
Supporting Links:
CloudTrail Events for Amazon EC2 Security Groups: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/security-group-control-access-to-instances.html#security-groups-commands
AWS CloudTrail: https://aws.amazon.com/cloudtrail/
Amazon EventBridge: https://aws.amazon.com/eventbridge/
Amazon SNS: https://aws.amazon.com/sns/
Question.43 A DevOps team manages an API running on-premises that serves as a backend for an Amazon API Gateway endpoint. Customers have been complaining about high response latencies, which the development team has verified using the API Gateway latency metrics in Amazon CloudWatch. To identify the cause, the team needs to collect relevant data without introducing additional latency. Which actions should be taken to accomplish this? (Choose two.) (A) Install the CloudWatch agent server side and configure the agent to upload relevant logs to CloudWatch. (B) Enable AWS X-Ray tracing in API Gateway, modify the application to capture request segments, and upload those segments to X-Ray during each request. (C) Enable AWS X-Ray tracing in API Gateway, modify the application to capture request segments, and use the X-Ray daemon to upload segments to X-Ray. (D) Modify the on-premises application to send log information back to API Gateway with each request. (E) Modify the on-premises application to calculate and upload statistical data relevant to the API service requests to CloudWatch metrics. |
43. Click here to View Answer
Answer: AC
Explanation:
The correct answer is AC. Here’s why:
A. Install the CloudWatch agent server side and configure the agent to upload relevant logs to CloudWatch. Installing the CloudWatch agent on the on-premises server allows you to capture logs directly from the API server without adding latency to the API’s response time. The agent can asynchronously upload these logs to CloudWatch. Analyzing these logs in CloudWatch will provide insights into server-side errors, slow queries, or other performance bottlenecks that contribute to the API latency. This is crucial because the API is on-premises, meaning direct access to the server logs is essential for troubleshooting.
C. Enable AWS X-Ray tracing in API Gateway, modify the application to capture request segments, and use the X-Ray daemon to upload segments to X-Ray. X-Ray allows you to trace requests from API Gateway through your backend application. Enabling X-Ray in API Gateway automatically instruments the API calls received by API Gateway. By modifying your application to generate and send request segments to X-Ray via the X-Ray daemon, you can gain visibility into how long the request spends in the on-premises application. The X-Ray daemon is optimized to efficiently handle the upload of trace data, minimizing the impact on the application’s performance. Crucially, X-Ray provides latency distribution, enabling efficient analysis to trace the root cause of API’s latency.
Why other options are not as suitable:
- B. Enable AWS X-Ray tracing in API Gateway, modify the application to capture request segments, and upload those segments to X-Ray during each request. While X-Ray tracing is beneficial, sending segments synchronously with each request directly from the application will significantly increase response latency, which directly contradicts the problem statement’s constraint. The X-Ray daemon is designed to handle the asynchronous upload of trace data to avoid this performance overhead.
- D. Modify the on-premises application to send log information back to API Gateway with each request. Sending log data to API Gateway during each request will significantly increase the API latency. API Gateway is designed to route API requests and not designed for log aggregation.
- E. Modify the on-premises application to calculate and upload statistical data relevant to the API service requests to CloudWatch metrics. While uploading metrics to CloudWatch is generally useful for monitoring, simply calculating and uploading aggregate statistics might not provide the detailed, granular insights required to pinpoint the cause of the latency. Moreover, calculating and uploading during each request cycle will add latency, which the problem statement wants to avoid. While helpful in the long run, it doesn’t directly address the initial problem of identifying the cause without introducing latency.
Supporting Documentation:
Amazon API Gateway CloudWatch Metrics: https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-metrics-and-dimensions.html
AWS X-Ray: https://docs.aws.amazon.com/xray/latest/devguide/aws-xray.html
Amazon CloudWatch Agent: https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Install-CloudWatch-Agent.html
Question.44 A company has an application that is using a MySQL-compatible Amazon Aurora Multi-AZ DB cluster as the database. A cross-Region read replica has been created for disaster recovery purposes. A DevOps engineer wants to automate the promotion of the replica so it becomes the primary database instance in the event of a failure. Which solution will accomplish this? (A) Configure a latency-based Amazon Route 53 CNAME with health checks so it points to both the primary and replica endpoints. Subscribe an Amazon SNS topic to Amazon RDS failure notifications from AWS CloudTrail and use that topic to invoke an AWS Lambda function that will promote the replica instance as the primary. (B) Create an Aurora custom endpoint to point to the primary database instance. Configure the application to use this endpoint. Configure AWS CloudTrail to run an AWS Lambda function to promote the replica instance and modify the custom endpoint to point to the newly promoted instance. (C) Create an AWS Lambda function to modify the application’s AWS CloudFormation template to promote the replica, apply the template to update the stack, and point the application to the newly promoted instance. Create an Amazon CloudWatch alarm to invoke this Lambda function after the failure event occurs. (D) Store the Aurora endpoint in AWS Systems Manager Parameter Store. Create an Amazon EventBridge event that detects the database failure and runs an AWS Lambda function to promote the replica instance and update the endpoint URL stored in AWS Systems Manager Parameter Store. Code the application to reload the endpoint from Parameter Store if a database connection fails. |
44. Click here to View Answer
Answer: D
Explanation:
The correct answer is D. Here’s a detailed justification:
Why Option D is Correct:
Option D provides a comprehensive and resilient solution for automating the promotion of an Aurora cross-Region read replica in the event of a primary database failure. It leverages several AWS services in a coordinated manner to achieve high availability and disaster recovery.
- AWS Systems Manager Parameter Store: Storing the Aurora endpoint in Parameter Store provides a centralized and secure location to manage the database connection string. Applications can retrieve the endpoint dynamically, eliminating the need for hardcoded values and simplifying updates.
- Amazon EventBridge: EventBridge allows for real-time event detection. By configuring an event rule to detect database failure events, the automation process is triggered immediately upon failure detection. This provides fast and reliable detection compared to polling mechanisms.
- AWS Lambda: Lambda provides the serverless compute required to orchestrate the promotion process. The Lambda function would perform the following actions:
- Promote the cross-Region read replica to become the new primary instance.
- Update the Aurora endpoint URL in AWS Systems Manager Parameter Store with the endpoint of the promoted instance.
- Application Logic: The application code is designed to handle database connection failures. Upon failure, the application would retrieve the updated endpoint from Parameter Store and attempt to reconnect, seamlessly switching to the newly promoted primary instance.
This solution is robust because it:
- Automates the Failover Process: Reduces manual intervention and minimizes downtime.
- Dynamically Updates the Connection String: Ensures applications always connect to the correct database instance.
- Leverages Event-Driven Architecture: Enables immediate reaction to database failures.
Why Other Options Are Incorrect:
- Option A: Route 53 latency-based routing is primarily designed for traffic distribution based on latency, not for automatic failover. While health checks can detect failure, the DNS propagation time might be significant, leading to prolonged downtime. CloudTrail, while providing auditing, is not the ideal trigger for immediate failover actions. Relying solely on SNS notifications from CloudTrail might introduce delays and unnecessary complexity.
- Option B: Custom endpoints are generally useful for directing specific types of traffic (e.g., read-only traffic), but they are not inherently designed for failover scenarios. Furthermore, modifying CloudFormation to promote the replica and update custom endpoint directly introduces potential risks and complexity.
- Option C: Modifying CloudFormation templates during a failover event introduces significant risks and potential delays. CloudFormation updates can be time-consuming and prone to errors. Relying on CloudWatch alarm and Lambda function to modify CloudFormation templates would be slow and complex for a database failover scenario.
Supporting Links:
Amazon Aurora Global Database: https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/aurora-global-database.html (Relevant for cross-region replication)
AWS Systems Manager Parameter Store: https://docs.aws.amazon.com/systems-manager/latest/userguide/systems-manager-parameter-store.html
Amazon EventBridge: https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-what-is.html
AWS Lambda: https://docs.aws.amazon.com/lambda/latest/dg/welcome.html
Question.45 A company hosts its staging website using an Amazon EC2 instance backed with Amazon EBS storage. The company wants to recover quickly with minimal data losses in the event of network connectivity issues or power failures on the EC2 instance. Which solution will meet these requirements? (A) Add the instance to an EC2 Auto Scaling group with the minimum, maximum, and desired capacity set to 1. (B) Add the instance to an EC2 Auto Scaling group with a lifecycle hook to detach the EBS volume when the EC2 instance shuts down or terminates. (C) Create an Amazon CloudWatch alarm for the StatusCheckFailed System metric and select the EC2 action to recover the instance. (D) Create an Amazon CloudWatch alarm for the StatusCheckFailed Instance metric and select the EC2 action to reboot the instance. |
45. Click here to View Answer
Answer: C
Explanation:
The correct answer is C: Create an Amazon CloudWatch alarm for the StatusCheckFailed System metric and select the EC2 action to recover the instance.
Here’s a detailed justification:
The key requirement is to recover quickly with minimal data losses from network or power failures on the EC2 instance.
- System Status Checks monitor the underlying EC2 host. Failures indicate problems with the hardware hosting your instance (network connectivity, power outage, hardware issues). The
StatusCheckFailed_System
metric specifically captures these system-level issues. - EC2 Recover action: When a
StatusCheckFailed_System
alarm triggers, the “Recover” action attempts to move the affected instance to new healthy hardware within the same Availability Zone. This is the fastest way to restore service because the underlying EBS volume remains attached, preserving data. It avoids the potentially longer time required to launch a new instance and restore from a snapshot. - Minimal Data Loss: Because the EBS volume isn’t detached during the recovery process, there is minimal data loss. Only the data in memory and in-transit that hasn’t yet been written to disk would be lost.
Why other options are incorrect:
- A: Placing the instance in an Auto Scaling group (ASG) with a capacity of 1 would replace the instance if it becomes unhealthy, but this is slower than recovery. The ASG needs to detect the failure, launch a new instance, and potentially configure it. Furthermore, restoring the data to the new instance requires a full boot process and copying data (from a snapshot or similar), leading to more downtime.
- B: Adding a lifecycle hook to detach the EBS volume before shutdown is counterproductive. Detaching the volume and then reattaching it adds considerable time and complexity to the recovery process. It doesn’t minimize downtime.
- D: Rebooting an instance (using
StatusCheckFailed_Instance
alarm) only addresses problems within the guest OS, not underlying hardware issues. It will not solve network connectivity issues or power failures affecting the host.StatusCheckFailed_Instance
measures the health of the instance itself, not the underlying system.
In summary, StatusCheckFailed_System
+ EC2 Recovery
offers the fastest path to recovery from underlying hardware problems (network, power) while keeping the EBS volume attached, minimizing data loss.
Authoritative Links:
EC2 Status Checks: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/monitoring-system-instance-status-check.html
EC2 Instance Recovery: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-recover.html
CloudWatch Metrics for EC2: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-cloudwatch-metrics.html