Some embodiments of the invention provide a method for collecting metric values relating to operations of a set of one or more resources executing on host computers in a datacenter. In some embodiments, the method hierarchically collects and analyzes samples, with a first set of samples collected and analyzed in the data plane, and a second set of samples collected and analyzed in the control plane by aggregating the samples collected in the data plane. In some embodiments, the data plane includes host computers on which sample collecting engines (e.g., service engines) execute, while the control plane includes a set of one or more servers that obtains sample data collected by the host computers, and aggregates and analyzes this data.