Your company operates a website for promoters to sell tickets for entertainment events. You are using a load balancer in front of an Auto Scaling group of web server. Promotion of popular events can cause surges of websites visitors. During scaling-out at theses times, newly launched instances are unable to complete configuration quickly enough, leading to user disappointment.
What option should you choose to improve scaling yet minimize costs? Choose 2 answers
A . Create an AMI with the application pre-configured. Create a new Auto Scaling launch configuration using this new AMI, and configure the Auto Scaling group to launch with this AMI
B . Use Auto Scaling pre-warming to launch instances before they are required. Configure pre-
warming to use the CPU trend CloudWatch metric for the group
C . Publish a custom CloudWatch metric from your application on the number of tickets sold, and create an Auto Scaling policy based on this
D . Using the history of past scaling events for similar event sales to predict future scaling requirements. Use the Auto Scaling scheduled scaling feature to vary the size of the fleet
E . Configure an Amazon S3 bucket for website hosting. Upload into the bucket an HTML holding page with its ‘x-amz-website-redirect-location’ metadata property set to the load balancer endpoint. Configure Elastic Load Balancing to redirect to the holding page when the load on web servers is above a certain level
Answer: D,E