Liqun -
There isn't the concept of a node in 7-mode, so there isn't an equivalent API.
There is the cf-get-partner API, to get the HA partner of a given system.
There's also the host-service-storage-system-list-* set of APIs for DFM.
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff, Sr.
Independent NetApp Consultant http://www.linkedin.com/in/eugenekashpureff
Senior NetApp Instructor, IT Learning Solutions http://sg.itls.asia/netapp
(P.S. I appreciate 'kudos' on any helpful posts.)