.. _config_cluster_manager_cds: Cluster discovery service ========================= The cluster discovery service (CDS) is an optional API that Envoy will call to dynamically fetch cluster manager members. Envoy will reconcile the API response and add, modify, or remove known clusters depending on what is required. .. note:: Any clusters that are statically defined within the Envoy configuration cannot be modified or removed via the CDS API. * :ref:`v2 CDS API ` Statistics ---------- CDS has a statistics tree rooted at *cluster_manager.cds.* with the following statistics: .. csv-table:: :header: Name, Type, Description :widths: 1, 1, 2 config_reload, Counter, Total API fetches that resulted in a config reload due to a different config update_attempt, Counter, Total API fetches attempted update_success, Counter, Total API fetches completed successfully update_failure, Counter, Total API fetches that failed because of network errors update_rejected, Counter, Total API fetches that failed because of schema/validation errors version, Gauge, Hash of the contents from the last successful API fetch control_plane.connected_state, Gauge, A boolean (1 for connected and 0 for disconnected) that indicates the current connection state with management server