anchor.diff:  * RDS Security group: Opens ingress `3306`, and everything for egress.
   
   
  -**Pre-requisites:** The CloudFormation template will require thr following:
  +**Pre-requisites:** The CloudFormation template will require the following:
   
   * A valid VPC
  -* A VPC Internet Gateway configured to access all the touside world
  +* A VPC Internet Gateway configured to access all the outside world
   * Valid subnets for the VPC as described above
   
   **Example:** Given a VPC with a CIDR of `192.168.0.0/16`
  
positive.code: = Installation via CloudFormation
  
  CloudFormation deployments leverage the capabilites of AWS infrastructure to provide a **prodution ready** deployment with a **1-click** button: Both Kill Bill and KAUI instances can be scaled up or down, and CloudWatch provides the requires metrics to follow what is happening, and the RDS database comes automatically configured and ready for use.
  
  == Overview of the Stack
  
  
negative.code: 
  * Kill Bill and Kaui on a custom AMI optimized for AWS workloads (integrated with CloudWatch, SQS, SES, X-Ray and more)
  * Auto Scaling Groups, to automatically scale up and down the number of instances as needed (such as when batches of invoices are generated)
  * A load balancer, integrated with our internal healthchecks to promptly take unhealthy instances out of rotation 
  * An RDS Aurora Cluster with automatic failover
  
  
  The following diagram shows the various AWS entities that will be created by CloudFormation:
  