Exam AWS Certified Solutions Architect - Associate SAA-C02 topic 1 question 221 discussion

Ans A https://aws.amazon.com/rds/features/multi-az/ To convert an existing Single-AZ DB Instance to a Multi-AZ deployment, use the "Modify" option corresponding to your DB Instance in the AWS Management Console.

A is correct, for all those are saying its B as A may cause some downtime, its absolutely wrong. from RDS FAQs below the explanation- Q: What happens when I convert my RDS instance from Single-AZ to Multi-AZ? For the RDS for MySQL, MariaDB, PostgreSQL and Oracle database engines, when you elect to convert your RDS instance from Single-AZ to Multi-AZ, the following happens: A snapshot of your primary instance is taken A new standby instance is created in a different Availability Zone, from the snapshot Synchronous replication is configured between primary and standby instances As such, there should be no downtime incurred when an instance is converted from Single-AZ to Multi-AZ. However, you may see increased latency while the data on the standby is caught up to match to the primary.

Convert Single-AZ to Multi-AZ "To convert an existing Single-AZ DB instance to a Multi-AZ deployment, modify your DB instance via the console, AWS CLI, or Amazon RDS API. These changes are applied during the next maintenance window unless you choose to apply them immediately." https://aws.amazon.com/blogs/database/best-practices-for-converting-a-single-az-amazon-rds-instance-to-a-multi-az-instance/#:~:text=To%20convert%20an%20existing%20Single,choose%20to%20apply%20them%20immediately. Impact of changing a Single-AZ instance to a Multi-AZ instance https://aws.amazon.com/premiumsupport/knowledge-center/rds-convert-single-az-multi-az/

Multi-AZ deployment : Downtime doesn't occur during this change. Console setting and description : 'Yes' to deploy your DB instance in multiple Availability Zones. Otherwise, 'No'. When the change occurs : If you choose to apply the change immediately, it occurs immediately.If you don't choose to apply the change immediately, it occurs during the next maintenance window. For more information, see Multi-AZ deployments for high availability. https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Overview.DBInstance.Modifying.html https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Concepts.MultiAZ.html

A - When a single-Az DB instance is converted to Multi-AZ deployment there isn't any downtime, just a little increased latency.

Agree. Ans = A. Reference: https://aws.amazon.com/rds/features/multi-az/ & https://cloudaffaire.com/aws-rds-multi-az/ (extra info)

"eliminate single points of failure" so that would mean Multi AZ "minimize database downtime" means quick recovery Only option A addresses these 2 points from the qn

A is correct

https://youtu.be/uiiS1h4PSI8 Yep its A. Watch the video and its so simple too!

A This action avoids downtime when you convert from Single-AZ to Multi-AZ, but you can experience a performance impact during and after converting to Multi-AZ. This impact can be significant for large write-intensive DB instances.

A is correct

why A has downtime?

A is the answer, it specifically states you can't change ANY application code. If you create a new RDS Multi AZ Deployment, how will the application know to send the data there if you cannot change the code? You're left with the only plausible answer, A.

Answer is A: You can use the console to convert existing DB instances to Multi-AZ deployments by modifying the DB instance and specifying the Multi-AZ option https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Concepts.MultiAZ.html

Ans A https://aws.amazon.com/rds/faqs/

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