multiple c-vols:
Oct 21 19:30:37.095967 np87be28cf22444 watcher-decision-engine[93381]: DEBUG watcher.decision_engine.model.collector.base [None req-53341e9d-85b9-43b8-a3cc-dc74f670dc84 None None] <ModelRoot>
Oct 21 19:30:37.095967 np87be28cf22444 watcher-decision-engine[93381]:   <StorageNode host="np47ad865b91dc4@lvmdriver-1" zone="nova" status="enabled" state="up" volume_type="['lvmdriver-1']" uuid="" human_id="">
Oct 21 19:30:37.095967 np87be28cf22444 watcher-decision-engine[93381]:     <Pool name="np47ad865b91dc4@lvmdriver-1#lvmdriver-1" total_volumes="1" total_capacity_gb="28" free_capacity_gb="28" provisioned_capacity_gb="0" allocated_capacity_gb="0" virtual_free="0" uuid="" human_id=""/>
Oct 21 19:30:37.095967 np87be28cf22444 watcher-decision-engine[93381]:   </StorageNode>
Oct 21 19:30:37.095967 np87be28cf22444 watcher-decision-engine[93381]:   <StorageNode host="np87be28cf22444@lvmdriver-1" zone="nova" status="enabled" state="up" volume_type="['lvmdriver-1']" uuid="" human_id="">
Oct 21 19:30:37.095967 np87be28cf22444 watcher-decision-engine[93381]:     <Pool name="np87be28cf22444@lvmdriver-1#lvmdriver-1" total_volumes="1" total_capacity_gb="28" free_capacity_gb="28" provisioned_capacity_gb="0" allocated_capacity_gb="0" virtual_free="0" uuid="" human_id=""/>
Oct 21 19:30:37.095967 np87be28cf22444 watcher-decision-engine[93381]:   </StorageNode>
Oct 21 19:30:37.095967 np87be28cf22444 watcher-decision-engine[93381]: </ModelRoot>
Oct 21 19:30:37.095967 np87be28cf22444 watcher-decision-engine[93381]:  {{(pid=93381) get_latest_cluster_data_model /opt/stack/watcher/watcher/decision_engine/model/collector/base.py:184}}

single c-vol in controller:
Oct 22 08:32:03.700763 np6144f3e50f784 watcher-decision-engine[92981]: DEBUG watcher.decision_engine.model.collector.base [None req-89db0006-10b9-4cae-b280-98c36f9c28c8 None None] <ModelRoot>
Oct 22 08:32:03.700763 np6144f3e50f784 watcher-decision-engine[92981]:   <StorageNode host="np6144f3e50f784@lvmdriver-1" zone="nova" status="enabled" state="up" volume_type="['lvmdriver-1']" uuid="" human_id="">
Oct 22 08:32:03.700763 np6144f3e50f784 watcher-decision-engine[92981]:     <Pool name="np6144f3e50f784@lvmdriver-1#lvmdriver-1" total_volumes="1" total_capacity_gb="28" free_capacity_gb="28" provisioned_capacity_gb="0" allocated_capacity_gb="0" virtual_free="0" uuid="" human_id=""/>
Oct 22 08:32:03.700763 np6144f3e50f784 watcher-decision-engine[92981]:   </StorageNode>
Oct 22 08:32:03.700763 np6144f3e50f784 watcher-decision-engine[92981]:   <StorageNode host="np6144f3e50f784@lvmdriver-2" zone="nova" status="enabled" state="up" volume_type="['lvmdriver-2']" uuid="" human_id="">
Oct 22 08:32:03.700763 np6144f3e50f784 watcher-decision-engine[92981]:     <Pool name="np6144f3e50f784@lvmdriver-2#lvmdriver-2" total_volumes="1" total_capacity_gb="28" free_capacity_gb="28" provisioned_capacity_gb="0" allocated_capacity_gb="0" virtual_free="0" uuid="" human_id=""/>
Oct 22 08:32:03.700763 np6144f3e50f784 watcher-decision-engine[92981]:   </StorageNode>
Oct 22 08:32:03.700763 np6144f3e50f784 watcher-decision-engine[92981]: </ModelRoot>