The following table highlights old vtctld API methods and their counterparts in the newer VTAdmin API.
Some methods do not have a 1:1 mapping from vtctld to VTAdmin. These cases include:
vtctld methods that are split out into many different VTAdmin methods (ex. keyspace and tablet action methods)
vtctld methods that are not supported in VTAdmin (ex. executing a vtctl command)
vtctld methods that we plan to support, but do not currently support, in VTAdmin
VTAdmin methods that were not supported by vtctld API; noted here because they may be useful
One of the main differences between vtctld and VTAdmin API is that VTAdmin API returns results across all clusters discovered by VTAdmin cluster discovery. VTAdmin API methods that accept a cluster_id parameter are methods that will return results from all clusters, unless the aforementioned filter parameter is provided.