Create Instances with an Affinity or Anti-Affinity Policy Using the API

You can place instances using affinity or anti-affinity by creating a server group in OpenStack and applying desired filter as a group policy. All instances that are members of the server group will be subject to the affinity or anti-affinity policy. You can perform this configuration using the ServerGroup API from the Python nova-client.

Prerequisites

• Verify that the intended anti-affinity filter configuration does not conflict with any existing administrative configuration, such as DRS rules that manage instance placement on hosts.

• Verify that you are running VMware Integrated OpenStack version 2.0.x or later.

• Verify that VMware Integrated OpenStack is running.

• Verify that you are using a Python nova-client version 2.17.0.6 or later, as required for the ServerGroup API. Go to http://docs.openstack.org/user-guide/common/cli_install_openstack_command_line_clients.html.

Procedure

1. Create a new server group with an anti-affinity policy.

   POST /v2/TENANT_ID/os-server-groups
   

   {
       "server_group": {
           "name": "SERVER_GROUP_NAME",
           "policies": ["POLICY_TYPE"]
       }
   }

   Option	Description
   TENANT_ID	ID value for the OpenStack tenant.
   SERVER_GROUP_NAME	Specify the name for the server group.
   POLICY_TYPE	Specify either affinity or anti-affinity.

2. Launch a new instance, including the os:scheduler_hints argument with the server group ID in the GET /servers command.

   ... "os:scheduler_hints": {"group": "SERVER_GROUP_UUID"}

3. (Optional) Confirm that the new rule and the server group instances appear and are running correctly in the VMware Integrated OpenStack deployment in vCenter.

   The rule details appear in the Manage > Settings > VM/Host Rules page for the Compute cluster.