Newly Released Amazon Web Services DVA-C02 Exam PDF

Using Lambda layers is a way to reduce the size of the deployment package and speed up the deployment process. Lambda layers are reusable components that can contain libraries, custom runtimes, or other dependencies. By using layers, the developer can separate the core function logic from the dependencies, and avoid uploading them every time the function code changes. Layers can also be shared across multiple functions or accounts, which can improve consistency and maintainability. References

• Working with AWS Lambda layers
• AWS Lambda Layers Best Practices
• Best practices for working with AWS Lambda functions

For in-place deployments, AWS CodeDeploy uses a set of predefined hooks that run in a specific order during each deployment lifecycle event. The hooks are ApplicationStop, BeforeInstall, AfterInstall, ApplicationStart, and ValidateService. The run order of the hooks for in-place deployments is as follows:

• ApplicationStop: This hook runs first on all instances and stops the current application that is running on the instances.
• BeforeInstall: This hook runs after ApplicationStop on all instances and performs any tasks required before installing the new application revision.
• AfterInstall: This hook runs after BeforeInstall on all instances and performs any tasks required after installing the new application revision.
• ApplicationStart: This hook runs after AfterInstall on all instances and starts the new application that has been installed on the instances.
• ValidateService: This hook runs last on all instances and verifies that the new application is running properly on the instances.

Amazon CloudWatch is a service that monitors AWS resources and applications. The developer can use CloudWatch to monitor and troubleshoot all applications from one place. To do so, the developer needs to download the CloudWatch agent to the on-premises server and configure the agent to use IAM user credentials with permissions for CloudWatch. The agent will collect logs and metrics from the on-premises server and send them to CloudWatch.

References:

• [What Is Amazon CloudWatch? - Amazon CloudWatch]
• [Installing and Configuring the CloudWatch Agent - Amazon CloudWatch]

AWS X-Ray automatically adds Region annotation for AWS services that are integrated with X-Ray. This annotation indicates the AWS Region where the service is running. The developer can use this annotation to filter and group traces by Region and identify any performance issues related to cross-Region calls. The developer can also add Region annotation for user-defined services by using the X-Ray SDK. This option enables the developer to implement distributed tracing for the application that runs across multiple AWS Regions. References

• AWS X-Ray Annotations
• AWS X-Ray Concepts