anchor.diff:  
   <%=vars.pcf_pools%>
   
  -#### <a id='databases'></a> Databases
  +### <a id='databases'></a> Databases
   
   For database services deployed outside Cloud Foundry, plan to leverage your infrastructure's high availability features and to configure backup and restore where possible. <%= vars.scaling_ert_db %>
   
  
positive.code: <%= vars.om_resurrector_header%>
  <%= vars.om_resurrector_text%>
  
  #### <a id='resource-pools'></a> Resource Pools
  
  To configure your resource pools according to the requirements of your deployment, see <%=vars.pools_link%>
  
  
negative.code: 
  <strong><%= modified_date %></strong>
  
  This topic describes the components used to ensure high availability in Cloud Foundry, vertical and horizontal scaling, and the infrastructure required to support scaling component VMs for high availability.
  
  
  ## <a id='components'></a> Components of a High Availability Deployment
  
  This section describes the system components needed to ensure high availability.
  
  ### <a id='azs'></a> Availability Zones
  
  During product updates and platform upgrades, the VMs in a deployment restart in succession, rendering them temporarily unavailable. During outages, VMs go down in a less orderly way. Spreading components across Availability Zones (AZs) and scaling them to a sufficient level of redundancy maintains high availability during both upgrades and outages and can ensure zero downtime.
  
  Deploying Cloud Foundry across three or more AZs and assigning multiple component instances to different AZ locations lets a deployment operate uninterrupted when entire AZs become unavailable. Cloud Foundry maintains its availability as long as a majority of the AZs remain accessible. For example, a three-AZ deployment stays up when one entire AZ goes down, and a five-AZ deployment can withstand an outage of up to two AZs with no impact on uptime.
  
  