By default, this test reports metrics for each cluster and for each service that is running on a cluster. Accordingly, ServiceName is the default selection from the ECS Filter drop-down. If you do not want service-level metrics, then you can configure the test to report resource usage at the cluster-level alone. For this, just select ClusterName from the ECS Filter drop-down. If this is done, then the test will only report cluster names as descriptors.