Exam AWS Certified Database - Specialty topic 1 question 182 discussion

Multi-AZ doesn't stop the outage. B is better however the solution doesn't explain all of the necessary steps e.g. create read replica and making it primary by failing over.

Only one answer provides high availability here.

Key word in the question is "to make the DB instance highly available until the sales event ends." hence answer is D

D is correct because that is the only option that makes the DB highly available. The requirement is "The company wants to minimize downtime for the DB instance and asks a database specialist to make the DB instance highly available until the sales event ends" The read replica needs manual effort to be promoted to primary. Hence B is wrong.

B is the correct answer How to minimize downtime using read replicas Typically in a self-managed or on-premises environment, a DBA minimizes downtime on an upgrade by using a rolling upgrade using read replicas. Amazon RDS doesn’t fully automate one-click rolling upgrades. However, you can still perform a rolling upgrade by creating a read replica, upgrading the replica, promoting the replica, and then routing traffic to the promoted replica. One other caveat about upgrade downtime is how Multi-AZ fits into the picture. One common fallacy is that Multi-AZ configurations prevents downtime during an upgrade. We do recommend that you use Multi-AZ for high availability, because it can prevent extended downtime due to hardware failure or a network outage. However, in the case of a MySQL or MariaDB engine upgrade, Multi-AZ doesn’t eliminate downtime. The slow shutdown and the physical changes made on the active server by the mysql_upgrade program require this downtime.

Reading through all of the comments and the link for /rds-required-maintenance page, it's obvious that multi az is the solution to "MINIMIZE" the down time.

A should be answer. As multi-az mode will update to both db engines.

https://aws.amazon.com/premiumsupport/knowledge-center/rds-required-maintenance/ multi AZ outage will be the time for failover (60 sec)

I'll go with B Using a read replica to reduce downtime when upgrading a MySQL database section - Using a read replica to reduce downtime when upgrading a MySQL database

It has to be D since this wording in the question is key "the maintenance update has been designated as necessary. "

question is missing more info A is good as you keep an environment that you know is working with D , you can't guaranty problem with the patch and need time to test it

i go with A, the update not not urgent so they can wait

D. With B, the database endpoint needs to be updated in the applications. That requires testing to ensure that the connectivity works.

I prefer B 1. This is "database" required maintenance. 2. Major DB engine you need both primary and read replica downtime 3. Miner DB engine upgrade you can upgrade read replica first. https://aws.amazon.com/blogs/database/best-practices-for-upgrading-amazon-rds-for-mysql-and-amazon-rds-for-mariadb/

Ans is D

This explains : https://aws.amazon.com/premiumsupport/knowledge-center/rds-required-maintenance/

I think A. https://aws.amazon.com/premiumsupport/knowledge-center/rds-mysql-downtime-impact/ "the DB engine version upgrade happens to both the primary and standby hosts at the same time. Therefore, a DB engine version upgrade doesn't benefit from a Multi-AZ deployment"