ANS-C01 Question 470
Select 3You are managing a critical web application running on Amazon EC2 instances behind an Application Load Balancer (ALB). The application has strict latency requirements, and any increase in latency must trigger an alert to the operations team. Which combination of steps would you take to set up an alerting mechanism that notifies the operations team if the ALB's target response time exceeds 500 milliseconds for 2 consecutive periods?
- A
Create a CloudWatch metric filter for the Application Load Balancer's 'TargetResponseTime' metric.
- B
Set up a CloudWatch Alarm on the 'TargetResponseTime' metric with a threshold of 500 milliseconds and a period of 1 minute.
- C
Configure the CloudWatch Alarm to evaluate the metric for 2 consecutive periods before triggering the alarm.
- D
Attach an Amazon SNS topic to the CloudWatch Alarm and subscribe the operations team to the topic.
- E
Enable logging on the ALB and use Amazon S3 to store the logs for retrospective analysis.
Show answer and explanation
Correct answers: B, C, D
Explanation
To set up an effective alerting mechanism for the ALB's latency, you must use CloudWatch metrics and alarms. The 'TargetResponseTime' metric is already available, so no additional metric filter is needed. A CloudWatch Alarm should be created with a threshold of 500 milliseconds and configured to evaluate the metric for 2 consecutive periods. Attaching an SNS topic ensures that notifications are sent to the operations team when the alarm is triggered. Logging and storing data in S3 is unrelated to real-time alerting.
- A. Incorrect.
Creating a metric filter is unnecessary in this case because the 'TargetResponseTime' metric is already available as a default metric for Application Load Balancers in CloudWatch.
- B. Correct.
This is correct because you need to set up a CloudWatch Alarm on the 'TargetResponseTime' metric with an appropriate threshold and period.
- C. Correct.
This is correct because you need to configure the alarm to evaluate the metric for 2 consecutive periods to avoid false positives and ensure consistent behavior before triggering the alarm.
- D. Correct.
This is correct because an Amazon SNS topic is required to notify the operations team when the alarm is triggered.
- E. Incorrect.
This is incorrect because enabling logging and storing logs in S3 is useful for troubleshooting and analysis but does not help with real-time alerting.