What API calls are executed while gathering inventory from a VMware ESX or a vCenter server?

Question

When the VMware infrastructure inventory task is run by a beacon to gather data from an ESX or vCenter server, what VMware API endpoints are called?

Answer

1. GetServiceContent - a single call to retrieve the ServiceInstance to enable further queries
2. RetrieveProperties - a single call, starting from the root folder and returning all HostSystem, Datacenter, Folder, ComputeResource and ClusterComputeResource objects (with 2-5 associated property values each) via recursive traversal specifications on:
   1. ComputeResource.host
   2. ClusterComputeResource.host
   3. Datacenter.hostFolder
   4. Datacenter.vmFolder
   5. Folder.childEntity to the above object types
3. Then for each HostSystem returned, an additional RetrieveProperties call, starting from the respective HostSystem object and returning all related VirtualMachine and ResourcePool objects (with 4 associated property values each) via recursive traversal specifications on:
   1. HostSystem.parent
   2. ComputeResource.resourcePool
   3. ResourcePool.resourcePool
   4. ResourcePool.vm

The base version 2.0 vSphere SOAP API is used for most calls, with one additional call per host and cluster to a later API method RetrievePropertiesEx to retrieve specific additional properties not available from the 2.0 API.