Exam AWS Certified Solutions Architect - Professional topic 1 question 398 discussion

B is correct. A: Does not address a loss of data since the last backup. B: Ensures that there are at least two EC instances, each of which is in a different AZ. It also ensures that the database spans multiple AZs. Hence this meets all the criteria. C: Having auto scaling set to a minimum instance count of one means that if there is just one instance and there is a problem, that instance will need to be restarted, meaning there would an outage during that restart time. As such, B is a better answer. D: Does not indicate that the two EC2 instances will be in different availability zones. If they are in the same AZ, that entire zone could theoretically have an outage. Given that, I would select B instead of D. Apart from that consideration D does the trick.

B There are 2 problems here. Firstly, the EBS snapshot is too old and secondly, the outage resulted in DB issues and data loss. Using 2 instances installed with the web server and using Route 53 load balancing should help with the first problem and RDS Multi-AZ DB would help in the second. A: This will not reduce the chances of lost data and downtime could still be significant and risky. B\D: I chose this simply because of the LB\Auto Scaling. While Route 53 can do similar function, it does not auto heal the instance to bring it back to healthy state. C: There is only 1 active instance, there should be at least 2.

Those who jumped on B are not considering the legacy app and the downtime, the app needs to be tested if you are downsizing the instance, yes its one instance, downtime will be the time it takes to respawn

Ensures that there are at least two EC instances

B correct.

The choice is clearly between B & C. I choose C for the following reasons- - You cannot downsize the EC2 instance m4.2xlarge to m4.xlarge and assume the legacy application will run fine. What if the legacy application requires minimum 32GB of memory to run or need minimum of 8 cores to run? You might break the legacy application if you downsize. - Similarly, you cannot assume that legacy application would work fine in an AutoScaling group. What about authentication, sessions and host of other adjustments you would need to make? - The question asks architectural changes to minimize downtime and reduce the chance of lost data and C accomplishes both - - It reduces downtime because the manual system operator's process would be automated with an AutoScaling Group. It will not be eliminated but minimized for sure. - It reduces the chance of losing data because the database is migrated to RDS.

It's B

Should be C. We need to minimize the downtime, not looking to provide HA capability. Autoscaling with 1 minimum will ensure, a new instance will be launched if something goes wrong.

I'll go with B

I think B is correct.

going with B

I go with B, the question is about HA, with two instances in two different AZd behind ALB it is achieved

I would say B.Ensures that there are at least two EC instances, each of which is in a different AZ. It also ensures that the database spans multiple AZs. Hence this meets all the criteria.

C looks better.. as option B and D are trying to run smaller instance for Legacy application. Legacy application doesnt support cluster because of session handling. SO C is not best option as it involve some downtime due to cooldown period but there will no data loss (which is the key) and this is best amongst given options.

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The answer should be B. The reasons are: 1) For minimum downtime -- Run the EC2 instances in an Auto Scaling group across multiple Availability Zones with a minimum instance count of two; 2) For avoiding loss of data -- Migrate the database to an Amazon RDS Oracle Multi-AZ DB instance.

B. Data loss is addressed with Oracle Multi AZ RDZ. Downtime minimized with ALB+ ASG of MINIMUM 2. C is having minimum of 1. D is not having ASG and inability to respawn instances.