Only CloudFormation's JSON Templates allow declarative version control of repeatably deployable models of entire AWS clouds.
https://blogs.aws.amazon.com/application-management/blog/category/Best+practices

To resolve a dependency error, add a DependsOn attribute to resources that depend on other resources in your template. In some cases, you must explicitly declare dependencies so that AWS CloudFormation can create or delete resources in the correct order. For example, if you create an Elastic IP and a VPC with an Internet gateway in the same stack, the Elastic IP must depend on the Internet gateway attachment. For additional information, see DependsOn Attribute.
http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/troubleshooting.html#trouble shootin g-errors-dependence-error

Explanation
When you add an Availability Zone to your load balancer. Clastic Load Balancing creates a load balancer
node in the Availability Zone. Load balancer nodes accept
traffic from clients and forward requests to the healthy registered instances in one or more Availability Zones.
For more information on adding AZ's to CLB, please refer to the below U RL:
* htto://docs aws.amazon.com/eiasticloadbaIancins/latest/classic/enable-disable-az.html

io1 volumes, or Provisioned IOPS (PIOPS) SSDs, are best for: Critical business applications that require
sustained IOPS performance, or more than 10,000 IOPS or 160 MiB/s of throughput per volume, like
large database workloads, such as MongoDB.
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSVolumeTypes.html

This is the ideal use case for AWS CloudTrail.
CloudTrail provides visibility into user activity by recording API calls made on your account.
CloudTrail records important information about each API call, including the name of the API, the identity of the caller, the time of the API call, the request parameters, and the response elements returned by the AWS service. This information helps you to track changes made to your AWS resources and to troubleshoot operational issues. CloudTrail makes it easier to ensure compliance with internal policies and regulatory standards.
https://aws.amazon.com/cloudtrail/faqs/