What is server immutability?

instance usage is considered temporary or ephemeral in nature for the period of deployment until the current release is active. During the new release, a new set of EC2 instances are rolled out by terminating older instances. This type of upgrade technique is more common in an immutable infrastructure. https://d0.awsstatic.com/whitepapers/overview-of-deployment-options-on-aws.pdf

You are building a game high score table in DynamoDB. You will store each user’s highest score for each game, with many games, all of which have relatively similar usage levels and numbers of players. You need to be able to look up the highest score for any game. What’s the best DynamoDB key structure?

access the highest value), your hash (partition) key should be the GameID, and there should be a range key for http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/GuidelinesForTables.html#GuidelinesForTables.

You need to perform ad-hoc business analytics queries on well-structured data. Data comes in constantly at a high velocity. Your business intelligence team can understand SQL. What AWS service(s) should you look to first?

supports ad-hoc queries over well-structured data using a SQL-compliant wire protocol, so the business team should be able to adopt this system easily. https://aws.amazon.com/kinesis/firehose/details/

Your application consists of 10% writes and 90% reads. You currently service all requests through a Route53 Alias
Record directed towards an AWS ELB, which sits in front of an EC2 Auto Scaling Group. Your system is getting very expensive when there are large traffic spikes during certain news events, during which many more people request to read similar data all at the same time. What is the simplest and cheapest way to reduce costs and scale with spikes like this?

reads and spikiness in demand. A cache behavior is the set of rules you configure for a given URL pattern based on file extensions, file names, or any portion of a URL path on your website (e.g., *.jpg). You can configure multiple cache behaviors for your web distribution. Amazon CloudFront will match incoming viewer requests with your list of URL patterns, and if there is a match, the service will honor the cache behavior you configure for that URL pattern. Each cache behavior can include the following Amazon CloudFront configuration values: origin server name, viewer connection protocol, minimum expiration period, query string parameters, cookies, and trusted signers for private content. https://aws.amazon.com/cloudfront/dynamic-content/

What method should I use to author automation if I want to wait for a CloudFormation stack to finish completing in a script?

is a real method, GetStackStatus / get-stack-status is not. http://docs.aws.amazon.com/cli/latest/reference/cloudformation/list-stacks.html

You have a high security requirement for your AWS accounts. What is the most rapid and sophisticated setup you can use to react to AWS API calls to your account?

a unified, near real-time stream for all API calls, which can be analyzed with any tool(s) of your choosing downstream. http://docs.aws.amazon.com/AmazonCloudWatch/latest/DeveloperGuide/EventTypes.html#api_event_type

If you’re trying to configure an AWS Elastic Beanstalk worker tier for easy debugging if there are problems finishing queue jobs, what should you configure?

queue is a queue where other (source) queues can send messages that for some reason could not be successfully processed. A primary benefit of using a dead letter queue is the ability to sideline and isolate the unsuccessfully processed messages. You can then analyze any messages sent to the dead letter queue to try to determine why they were not successfully processed. http://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features-managing-env-tiers.html#worker-deadletter

Your CTO is very worried about the security of your AWS account. How best can you prevent hackers from completely hijacking your account?

resources. MFA adds extra security because it requires users to enter a unique authentication code from an approved authentication device or SMS text message when they access AWS websites or services. http://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_mfa.html

You need the absolute highest possible network performance for a cluster computing application. You already selected homogeneous instance types supporting 10 gigabit enhanced networking, made sure that your workload was network bound, and put the instances in a placement group. What is the last optimization you can make?

throughput possible, and they are recommended in this case. For more information, see Placement Groups. http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/network_mtu.html#jumbo_frame_instances

Your application’s Auto Scaling Group scales up too quickly, too much, and stays scaled when traffic decreases. What should you do to fix this?

need to set the thresholds of the metric based on whether or not latency is affected by the change, to justify adding capacity instead of wasting money. http://docs.aws.amazon.com/AutoScaling/latest/DeveloperGuide/policy_creating.html