AWS Certified Sysops Administrator Associate · Free Practice Question Medium
Question 49
You work for a blockchain company and you have a ledger application that is memory intensive. It is exposed in an auto scaling group behind an AWS load balancer. You would like to auto scale your application based on the number of users that you have.
As a SysOps Administrator, which of the following would you recommend to meet this requirement?
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A
Deploy a script on the Load Balancer to expose the number of users that are connected to your application as a custom CloudWatch metric
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B
Use the RAM usage CloudWatch metric directly from the Load Balancer and auto scale based on that
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C
Auto Scale based on the number of connections CloudWatch metric for the Load Balancer
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D
Push the RAM usage as a custom metric for the Load Balancer and auto scale based on that
Reveal correct answer
Correct answer: C
Explanation
Correct option:
Auto Scale based on the number of connections CloudWatch metric for the Load Balancer
Elastic Load Balancing publishes metrics to Amazon CloudWatch for your load balancers and your targets. Elastic Load Balancing reports metrics to CloudWatch only when requests are flowing through the load balancer. If there are requests flowing through the load balancer, Elastic Load Balancing measures and sends its metrics in 60-second intervals. If there are no requests flowing through the load balancer or no data for a metric, the metric is not reported.
For the given use-case, you can use the ActiveConnectionCount metric to auto scale. This metric represents the total number of concurrent TCP connections active from clients to the load balancer and from the load balancer to targets.
Incorrect options:
Push the RAM usage as a custom metric for the Load Balancer and auto scale based on that
Use the RAM usage CloudWatch metric directly from the Load Balancer and auto scale based on that
Both these options advocating RAM usage as a metric are incorrect since the use-case refers to the auto scaling criteria based on the number of users which is better represented by the ActiveConnectionCount metric.
Deploy a script on the Load Balancer to expose the number of users that are connected to your application as a custom CloudWatch metric - This option has been added as a distractor as you cannot deploy a script on a Load Balancer.
Reference:
Discussion
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