anchor.diff:  
   <p class="note"><b>Note:</b> Always use an odd number of AZs. This ensures that your deployment remains available when greater than half of the AZs are available. For example, a deployment with three AZs stays available when one AZ goes down and two AZs are still available.</p>
   
  -## <a id='external-lbs'></a> External Load Balancers for High Availability
  +### <a id='external-lbs'></a> External Load Balancers
   
   External load balancers distribute traffic coming from the internet to your internal network. 
   
  
positive.code: 
  You can horizontally scale most <%= vars.product_short %> component VMs to multiple instances for high availability. 
  
  You should also distribute the instances of components across different AZs to minimize downtime during ongoing operation, product updates, and platform upgrades. For more information about using AZs, see [Availability Zones for High Availability](#azs).
  
  <%= vars.scaling_ert %>
  
  <%= partial vars.scale_table %>
  
  
  ## <a id='supporting-scaling'></a> Support Component Scaling
  
  The ability to scale component VMs is important for high availability. 
  
  To scale component VMs, you must ensure that the surrounding infrastructure of your deployment supports VM scaling.
  
  This section describes the infrastructure required to support scaling component VMs for high availability.
  
  
negative.code: 
  <%= vars.external_lb %>
  
  ### <a id='blobstore'></a> External Blob Storage
  
  Blobs are large binary files. To store blobs for high availability, use external storage such as Amazon S3 or an S3-compatible service. 
  
  