We get configuration details on all servers in a single API call by calling compute servers-detail /servers/detail ( https://docs.openstack.org/api-ref/compute/?expanded=list-servers-detail,list-servers-detailed-detail#list-servers-detailed )

However, it provides only configuration data, not runtime metrics.

For runtime metrics, compute diagnostics API /servers/{server_id}/diagnostics ( https://docs.openstack.org/api-ref/compute/?expanded=show-server-diagnostics-detail#show-server-diagnostics ) can be used.

It requires server_id to be passed and each API call will be separate for each instance.

It is good to have an API to get this diagnostics information for all the instances with a single API call like /servers/detail.