I am trying to update a stack using openstack heat templates to bring up and configure new nova Servers as a part of existing Server Group. When added configuration information(for new nova Servers) in the templates which are shared by existing and new VMs, the existing nova Servers are also affected and re-spawned. Is there any way to restrict the openstack from re-spawning or manipulating the existing nova servers of the stack?
Adding the following tag to the OS::Nova::Server properties prevented the re-spwaning of the existing instances.
user_data_update_policy: IGNORE