anchor.diff:  
   All other options will disappear. Click *Launch*.
   
  -The next page is titled *Choose Instance Type*. Your instance type is already chosen, so click *Configure Instance Details* at the bottom of the page.
  -
  -The next page will provide you with a long list of options. The first option is *Number of Instances*. Set the number of instances you wish to launch. Each instance will have essentially the same configuration, including the same image, the same subnet and availability zone, and the same security group.
  -
  -After setting the number of instances, scroll down to the bottom of the page. The last section is titled *Advanced Settings*. In this section you should set the configuration file you produced above. The setting panel should look like this:
  -
  -image:https://github.com/killbill/killbill-docs/raw/v3/userguide/assets/aws/multitier-userdata.png[align=center]
  -
  -Now click *Review and Launch* at the bottom of the page. The following page is headed *Review Instance Launch*. This provides a chance to review the details of your chosen instances. Then click *Launch* at the bottom of the page.
  -
  -==== 3. Setup a Key Pair
  -
  -Next you will see a very important popup that asks you to choose or create a *key pair*.
  -
  -image:https://github.com/killbill/killbill-docs/raw/v3/userguide/assets/aws/multitier-keypair.png[align=center]
  -
  -The key pair provides the credentials you will need to login to your EC2 instances. 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. All your instances can use the same one. 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 instances.
  -
  -==== 4. Launch your Instances
  +The next page is headed *Launch an Instance*. There ar several things you will need to do here.
  +
  +First, at the top right, select the number of instances you will use. We recommend 2. You can add more later.
  +
  +Next, scroll down to the middle of this page, to the box titled *Key Pair (login)* Here you are asked to choose or create a *key pair*.
  +
  +image:https://github.com/killbill/killbill-docs/raw/v3/userguide/assets/aws/single-tier-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 https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html[AWS documentation]. We recommend that you create a new key pair. Click *Create Key Pair* to display a pane to be used for the creation. Give the key pair a simple, easy to remember name such as `My-Key-Pair`. Do not change the other options on this pane. 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.
  +
  +Finally, scroll to the bottom and open the section labeled *Advanced Details*. You will see a long list of settings. At to the very bottom of this list is a box headed *User Settings*. Copy your configuration file into this box.
  +
  +==== 3. Launch your Instances
   
   When the key pair is generated, click *Launch Instances*. You should see the screen below:
   
  -image:https://github.com/killbill/killbill-docs/raw/v3/userguide/assets/aws/multitier-launching.png[align=center]
  +image:https://github.com/killbill/killbill-docs/raw/v3/userguide/assets/aws/singletier-launching.png[align=center]
   
   Your instances are finally launching! To follow what is happening on the EC2 Dashboard, scroll all the way down to the bottom, and click *View Instance* at the bottom right. This will take you to the *Instances* screen which is part of the EC2 Dashboard.
   
   image:https://github.com/killbill/killbill-docs/raw/v3/userguide/assets/aws/multitier-instances.png[align=center]
   
   
  -In a short time, the *Instance State* for each instance should indicate *Running*. You will need to scroll to the right to see all of the information available about your instances.
  -
  -==== 5. Setup Security Rules
  -
  -You are almost set, but there is one more thing you need to do, and that is to scroll down in the menu on the left side to select *Security Groups*. You should see a list of two or more groups. Select the group whose name begins with `Kill Bill on AWS`, then scroll to the bottom and select the tab for *Inbound Rules*. You should see:
  +In a short time, the *Instance State* for each instance should indicate *Running*. You will need to scroll to the right to see all of the information available about your instances. In particular, make a note of the *Availability Zone* (such as `us-east-1a`) assigned to each instance. You will need this information later.
  +
  +==== 4. Setup Security Rules
  +
  +The next step is to scroll down in the menu on the left side to select *Security Groups*. You should see a list of two or more groups. Select the group whose name begins with `Kill Bill on AWS`, then scroll to the bottom and select the tab for *Inbound Rules*. You should see:
   
   image:https://github.com/killbill/killbill-docs/raw/v3/userguide/assets/aws/multitier-inbound-original.png[align=center]
   
  
positive.code: image:https://github.com/killbill/killbill-docs/raw/v3/userguide/assets/aws/multitier-inbound-new.png[align=center]
  
  
  ==== 6. Login to an Instance
  
  Now that your instances are set up, you need to ensure that you can login to them for configuration and maintenance when needed. To login, use the secure shell command:
  
  
negative.code: First, you need to edit the database properties. DB_SERVER should be set to the full name of the DB instance, as given in the *Connectivity and Security* panel (see above). The port number 3306 is required. DB_USER and DB_PASSWORD should be set to the administrator credentials you have chosen for the RDS instance.
  
  Second, you may optionally edit any Kill Bill properties that you need to change from the standard defaults. For more information see the https://docs.killbill.io/latest/userguide_configuration.html[Kill Bill Configuration Guide].
  
  Save this script in a text file. You will need it in the next step.
  
  === Launch EC2 Instances
  
  