AWS-SysOps Exam Dumps Sample Questions

AWS-SysOps Question 8


You have an Auto Scaling group associated with an Elastic Load  Balancer (ELB). You have no- ticed that instances launched via the Auto Scaling group are being marked  unhealthy due to an ELB health check, but these unhealthy instances are not being terminated.
What do you need to do to ensure trial instances marked unhealt hy by the ELB will be termi- nated and replaced?


A. Change the thresholds set on the Auto Scaling group health check
B. Add an Elastic Load Balancing health check to your Auto Scaling group
C. Increase the value for the Health check interval set on the Elastic Load Balancer
D. Change the health check set on the Elastic Load Balancer to use TCP rather than HTTP checks


Correct Answer: B
Explanation/Reference:
http://docs.aws.amazon.com/AutoScaling/latest/DeveloperGuide/as-add-elb-healthcheck.html
Add an Elastic Load Balancing Health Check to your Auto Scaling Group
By default, an Auto Scaling group periodically reviews the resu lts of EC2 instance status to determine the health state of each instance. However, if you have associated  your Auto Scaling group with an Elastic Load Balancing load balancer, you can choose to use the Elastic  Load Balancing health check. In this case, Auto Scaling determines the health status of your instanc es by checking the results of both the EC2 instance status check and the Elastic Load Balancing instance h ealth check.
For information about EC2 instance status checks, see Monitor I nstances With Status Checks in the Amazon EC2 User Guide for Linux Instances. For information abou t Elastic Load Balancing health checks, see Health Check in the Elastic Load Balancing Developer Guide.
This topic shows you how to add an Elastic Load Balancing healt h check to your Auto Scaling group, assuming that you have created a load balancer and have registe red the load balancer with your Auto Scaling group. If you have not registered the load balancer wit h your Auto Scaling group, see Set Up a Scaled and Load-Balanced Application.
Auto Scaling marks an instance unhealthy if the calls to the Am azon EC2 action DescribeInstanceStatus return any state other than running, the system status shows im paired, or the calls to Elastic Load Balancing action DescribeInstanceHealth returns OutOfService in  the instance state field.
If there are multiple load balancers associated with your Auto  Scaling group, Auto Scaling checks the health state of your EC2 instances by making health check calls  to each load balancer. For each call, if the Elastic Load Balancing action returns any state other than InSe rvice, the instance is marked as unhealthy. After Auto Scaling marks an instance as unhealthy, it remains i n that state, even if subsequent calls from other load balancers return an InService state for the same ins tance.