When I am going to delete the group instance it always failed. The notification is that, but the problem is that I can not find the 'projects/windowtrafic/global/backendServices/backend' in google console.
The notification message:
The instance_group_manager resource 'projects/windowtrafic/regions/asia-east1/instanceGroupManagers/instance-group-cchatty' is already being used by 'projects/windowtrafic/global/backendServices/backend'