DOP-C02 Exam Dumps : AWS Certified DevOps Engineer - Professional

You can run custom recipes manually, but the best approach is usually to have AWS OpsWorks Stacks run them automatically. Every layer has a set of built-in recipes assigned each of five lifecycle events—Setup, Configure, Deploy, Undeploy, and Shutdown. Each time an event occurs for an instance, AWS OpsWorks Stacks runs the associated recipes for each of the instance ' s layers, which handle the corresponding tasks. For example, when an instance finishes booting, AWS OpsWorks Stacks triggers a Setup event. This event runs the associated layer ' s Setup recipes, which typically handle tasks such as installing and configuring packages

To allow an EC2 instance to access CodeArtifact, an IAM role attached via an instance profile must be granted permissions to access the CodeArtifact repository. The EC2 instance assumes this role.

The instance then uses the AWS CLI command aws codeartifact login to authenticate and configure the package manager (e.g., pip) to use the CodeArtifact repository. This command obtains an authorization token and sets up repository credentials securely on the instance.

Service-linked roles (Option A) are managed by AWS services, not used for instance access. CodeArtifact does not support ACLs (Option C), and resource-based policies (Option B) do not grant access to EC2 instances by principal.

This method is standard for securely managing credentials and access to CodeArtifact in automated deployments.

The Amazon SQS service publishes several standard CloudWatch metrics by default, including ApproximateNumberOfMessagesVisible, which represents the number of messages available for retrieval from the queue (i.e., the number of messages waiting to be processed). This is the primary metric to monitor queue backlog and processing delays.

Using ApproximateNumberOfMessagesVisible to monitor the visible messages in the queue gives a direct and near real-time indication of processing delays or backlog.

CloudWatch metrics are automatically collected and available without the need to create custom metrics or Lambda functions, which increases operational efficiency by reducing complexity and maintenance overhead.

Setting a CloudWatch alarm on this metric with a static threshold and a reasonable evaluation period (such as 1 hour) is sufficient to alert the team when the queue grows beyond an expected size.

The alarm can be directly configured to send notifications to an existing SNS topic, maintaining seamless integration with the team’s alerting mechanisms.

The ApproximateNumberOfMessagesDelayed metric refers to messages that are delayed and not available for processing yet due to delay settings, which is not the direct backlog that causes business process delays.

Options C and D introduce unnecessary complexity by requiring Lambda functions and custom metrics or scheduled invocations, which reduce operational efficiency compared to using built-in CloudWatch metrics and alarms.

Reference from AWS Official Documentation and Study Guide:

Amazon SQS Monitoring with CloudWatch Metrics: " Amazon SQS automatically sends metrics to CloudWatch, including ApproximateNumberOfMessagesVisible, which shows the number of messages available for retrieval. " (Source: Amazon SQS Monitoring - AWS Documentation)

Setting CloudWatch Alarms for SQS Queues: " You can create CloudWatch alarms on SQS metrics such as ApproximateNumberOfMessagesVisible to receive notifications when the queue size exceeds a threshold. " (Source: Amazon CloudWatch Alarms - AWS Documentation)

AWS DevOps Engineer Professional Exam Guide: " Efficient alerting for queue backlogs should leverage native CloudWatch metrics to minimize operational overhead. " (Source: Official AWS Certified DevOps Engineer Professional Study Guide)