Services shown in the Down state indicate that there are 0 service instances announcing into the mesh. This would be seen anytime the service is no longer deployed (scaled to 0) but has not been removed from catalog. Additionally, this can be seen if the catalog entry doesn't properly match the announced service information.
The warning state indicates that a service has been under or over provisioned within the mesh. The acceptable provisioned range is set with the
maxInstances field of the Catalog service entry
Services in a stable state have no known issues with their deployment.