Amazon Web Services Updated CLF-C02 Exam Questions and Answers by md

Understanding Availability Zones (AZs): An Availability Zone is a distinct location within an AWS region that is engineered to be isolated from failures in other AZs.

Characteristics of Availability Zones:

Data Centers: Each AZ consists of one or more discrete data centers with redundant power, networking, and connectivity.

High Availability: AZs are designed for high availability, providing low-latency network connections to other zones in the same region.

Fault Isolation: They provide fault isolation and are used to deploy applications and services to ensure high availability and reliability.

Use Cases for Availability Zones:

Multi-AZ Deployments: For services like RDS, deploying in multiple AZs ensures fault tolerance.

Disaster Recovery: Setting up resources in multiple AZs helps in quick recovery from failures.

Load Balancing: Distributing traffic across AZs using Elastic Load Balancing ensures optimal performance and availability.

References:

AWS Global Infrastructure

Understanding AWS Regions and Availability Zones

AWS Cloud Adoption Framework (AWS CAF) is a tool that helps organizations understand how cloud adoption transforms the way they work, and it provides structure to identify and address gaps in skills and processes. Applying the AWS CAF in your organization results in an actionable plan that helps you prepare the cloud environment, enable your staff with new skills, and migrate your applications. AWS Pricing Calculator is a tool that helps you estimate the cost of AWS services for your use cases and compare the cost of different AWS service configurations. AWS Well-Architected Framework is a tool that helps you review and improve your cloud-based architectures and better understand the business impact of your design decisions. AWS Budgets is a tool that helps you plan your service usage, service costs, and instance reservations, and track how close your plan is to your budgeted amount.

Amazon EC2 is a web service that provides secure, resizable compute capacity in the cloud. It allows you to launch virtual servers, called instances, with different configurations of CPU, memory, storage, and networking resources. AWS Compute Optimizer analyzes the specifications and utilization metrics of your Amazon EC2 instances and generates recommendations for optimal instance types that can reduce costs and improve performance. You can view the recommendations on the AWS Compute Optimizer console or the Amazon EC2 console12.

Amazon RDS, Amazon Lightsail, and AWS Step Functions are not supported by AWS Compute Optimizer. Amazon RDS is a managed relational database service that lets you set up, operate, and scale a relational database in the cloud. Amazon Lightsail is an easy-to-use cloud platform that offers everything you need to build an application or website, plus a cost-effective, monthly plan. AWS Step Functions lets you coordinate multiple AWS services into serverless workflows so you can build and update apps quickly3 .

AWS Database Migration Service (AWS DMS) is a managed and automated service that helps you migrate your databases from your on-premises or cloud environment to AWS, either as a one-time migration or as a continuous replication. AWS DMS supports migration between 20-plus database and analytics engines, such as PostgreSQL, Oracle, MySQL, SQL Server, MongoDB, Amazon Aurora, Amazon RDS, Amazon Redshift, and Amazon S3. AWS DMS also provides schema conversion and validation tools, as well as monitoring and security features. AWS DMS is a cost-effective and reliable solution for database migration, as you only pay for the compute resources and additional log storage used during the migration process, and you can minimize the downtime and data loss with Multi-AZ and ongoing replication12

To migrate a PostgreSQL database from on-premises to Amazon RDS using AWS DMS, you need to perform the following steps:

Create an AWS DMS replication instance in the same AWS Region as your target Amazon RDS PostgreSQL DB instance. The replication instance is a server that runs the AWS DMS replication software and connects to your source and target endpoints. You can choose the instance type, storage, and network settings based on your migration requirements3

Create a source endpoint that points to your on-premises PostgreSQL database. You need to provide the connection details, such as the server name, port, database name, user name, and password. You also need to specify the engine name as postgres and the SSL mode as required4

Create a target endpoint that points to your Amazon RDS PostgreSQL DB instance. You need to provide the connection details, such as the server name, port, database name, user name, and password. You also need to specify the engine name as postgres and the SSL mode as verify-full.

Create a migration task that defines the migration settings and options, such as the replication instance, the source and target endpoints, the migration type (full load, full load and change data capture, or change data capture only), the table mappings, the task settings, and the task monitoring role. You can also use the AWS Schema Conversion Tool (AWS SCT) to convert your source schema to the target schema and apply it to the target endpoint before or after creating the migration task.

Start the migration task and monitor its progress and status using the AWS DMS console, the AWS CLI, or the AWS DMS API. You can also use AWS CloudFormation to automate the creation and execution of the migration task.

The other options are not suitable for migrating a PostgreSQL database from on-premises to Amazon RDS. Cloud Adoption Readiness Tool is a tool that helps you assess your readiness for cloud adoption based on six dimensions: business, people, process, platform, operations, and security. It does not perform any database migration tasks. AWS Migration Hub is a service that helps you track and manage the progress of your application migrations across multiple AWS and partner services, such as AWS DMS, AWS Application Migration Service, AWS Server Migration Service, and CloudEndure Migration. It does not perform any database migration tasks itself, but rather integrates with other migration services. AWS Application Migration Service is a service that helps you migrate your applications from your on-premises or cloud environment to AWS without making any changes to the applications, their architecture, or the migrated servers. It does not support database migration, but rather replicates your servers as Amazon Machine Images (AMIs) and launches them as EC2 instances on AWS.

References: AWS Database Migration Service, What is AWS Database Migration Service?, Working with an AWS DMS replication instance, Creating source and target endpoints for PostgreSQL, [Creating a target endpoint for Amazon RDS for PostgreSQL], [Creating a migration task for AWS DMS], [AWS Schema Conversion Tool], [Starting a migration task for AWS DMS], [AWS CloudFormation], [Cloud Adoption Readiness Tool], [AWS Migration Hub], [AWS Application Migration Service]