anchor.diff:  Datadog can be integrated with several types of Kill Bill installations. In this guide we discuss the use of datadog to manage metrics produced
   by two types of implementations on Amazon Web Services (AWS):
   Single Tier and Multitier. With the latest Amazon Machine Image (AMI)
  -for Kill Bill, it is very easy to direct the Kill Bill metrics to
  -Datadog and work with them in the way that best suits your needs.
  +for Kill Bill, the application is preconfigured to collect these metrics and to direct them to Datadog once authorization is provided.
   
  -== Check Your Kill Bill Version
  -
  -We assume that you have a working Kill Bill implementation running on
  -AWS, using either the
  -https://docs.killbill.io/latest/aws-singletier.html[Single Tier] or
  -https://docs.killbill.io/latest/aws-multitier.html[Multitier]
  -installation options. The single tier option runs Kill Bill, Kaui, the
  -MariaDB database and the nginx load balancer on a single AWS EC2
  -instance. This is suitable for quick deployment and for testing and
  -development. The multitier option runs Kill Bill and Kaui on two or more
  -separate EC2 instances, and uses an AWS RDS database manager along with
  -an AWS load balancer. This is an attractive option for many production
  -uses.
  -
  -You should be running Kill Bill version 2021.9 or later. This version
  -can be configured to provide its full collection of Kill Bill metrics to
  -Datadog (and several other analysis tools). If you open the Kill Bill
  -admin page in your browser, it should show that you are
  -running the "Kill Bill Premium edition":
  -
  -image::metrics-kb-admin.png[align=center]
  -
  -
  -If you see this page you are ready to go. If not, you should upgrade
  -your installation.
  -
  -While you are on this page, if you want to see all the metrics that Kill
  -Bill has to offer, just add the path `/1.0/metrics` to the URL. Have fun!
  -If you find these hard to understand, though, maybe datadog can help.
  -
  + 
   == Set Up Datadog
   
   You may already be familiar with datadog. If not, this section will
  
positive.code: 
  == Single Tier and Multitier Implementations
  
  Measurements and metrics are an important part of managing your Kill
  Bill system to be sure that performance is optimized and any problems
  can be detected early. Kill Bill collects over 1,300 metrics to show you
  every conceivable view of your system's behavior.
  
  Several third party tools are available to manage and display metrics of
  this type. One popular tool is https://www.datadoghq.com/[Datadog]. This
  package offers a low-cost option to monitor and display whatever metrics
  you may find useful from the Kill Bill collection, including metrics
  
negative.code: 
  ```
  -Dcom.killbill.datadog.enable=true
  -Dcom.killbill.datadog.apiKey=Your-API-Key
  ```
  
  The API key to be added is the same one contained in the command you
  