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   image:https://github.com/killbill/killbill-docs/raw/v3/userguide/assets/aws/single-ami-keypair.png[align=center]
   
  -The key pair provides the credentials you will need to login to your EC2 instance. For details about key pairs, see the [AWS documentation](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html). We recommend that you create a new key pair. Give the key pair a simple, easy to remember name such as `My-Key-Pair`. Then click **Download Key Pair**. Important: You *must* save the private key that will be generated in this step. If you lose this key, you will *not* be able to login to your instance.
  +The key pair provides the credentials you will need to login to your EC2 instance. For details about key pairs, see the https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html[AWS documentation]. We recommend that you create a new key pair. Give the key pair a simple, easy to remember name such as `My-Key-Pair`. Then click **Download Key Pair**. Important: You *must* save the private key that will be generated in this step. If you lose this key, you will *not* be able to login to your instance.
   
   When the key pair is generated, click **Launch Instances**. You should see the screen below:
   
  
positive.code: 
  == Overview
  
  Single AMI deployments are a way to deploy the Kill Bill stack, that is both the Kill Bill server and the administrative UI (KAUI), from one AMI. We offer two options. The `Single-Tier` option uses only a single `ec2` instance. This is suitable for testing and experiments. The `Multi-Tier` option uses two or more `ec2` instances, and is designed for production deployments. Both of these deployment options rely on the same underlying AMI, but for the `Multi-Tier` option there is a list of prerequisites, such as an external database, along with a startup script to be provided when launching the instance.
  
  
  == Single-Tier Deployments
  
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  image:https://github.com/killbill/killbill-docs/raw/v3/userguide/assets/aws/single-tier-ami_deployment.png[align=center]
  
  In this model, the Kill Bill server and KAUI are deployed within the `tomcat` application server. Requests are handled by `nginx`. Requests received on port 443 are delivered to KAUI, and those received on port 8443 are delivered to Kill Bill. Both Kill Bill and KAUI communicate as needed with the `mysql` database.  
  
  === Getting Started
  
  
  To start the installation process, point your browser to +++<a href="https://aws.amazon.com/marketplace/pp/B083LYVG9H?ref=_ptnr_doc_" onclick="getOutboundLink('https://aws.amazon.com/marketplace/pp/B083LYVG9H?ref=_ptnr_doc_'); return false;">AWS Marketplace</a>+++: 
  
  If you are new to AWS, you will be asked to create an account and provide billing information. Once your account is validated,
  you should see the following image at the top of your screen:
  
  image:https://github.com/killbill/killbill-docs/raw/v3/userguide/assets/aws/single-ami-subscribe.png[align=center]
  
  