Enable Cross-AZ high availability for DHCP¶

This section describes how to enable Cross-AZ high availability for DHCP. As a result, DHCP services will be created in availability zones selected during the network creation.

To enable Cross-AZ high availability for DHCP:

1. Log in to the Salt Master node.

2. In /srv/salt/reclass/classes/cluster/<cluster_name>/openstack/control.yml, set the following parameters:

   parameters:
     neutron:
       server:
         dhcp_agents_per_network: '2'
         dhcp_load_type: 'networks'
         network_scheduler_driver: neutron.scheduler.dhcp_agent_scheduler.AZAwareWeightScheduler
   

3. In /srv/salt/reclass/classes/cluster/<cluster_name>/infra/config/nodes.yml, set the availability_zone parameter for each network or gateway node as required:

   parameters:
     reclass:
       storage:
         node:
           ...
           openstack_gateway_node<id>:
             parameters:
               neutron:
                 gateway:
                   availability_zone: <az-name>
           openstack_gateway_node<id+1>:
             parameters:
               neutron:
                 gateway:
                   availability_zone: <az-name>
          ...
   

4. Apply the changes:

   salt -C 'I@salt:master' state.sls reclass.storage
   salt -C 'I@neutron:server or I@neutron:gateway' saltutil.refresh_pillar
   salt -C 'I@neutron:server or I@neutron:gateway' state.sls neutron