So, what we are expecting from VCS is the endpoints that returns JSON data in a format as mentioned in its documentation. More specifically, here we are looking for the endpoints with yourdomainoripaddress/key/[key] pattern. Supposing you have varnish enterprise and VCS running and have some traffic through Varnish Enterprise, yourdomainoripaddress/key/ALL should return JSON data in the format mentioned above. You can read more in the documentation.
Another thing that needs to be configured is “vcs-unique-id” key; otherwise the “n_req_uniq” in the JSON data will be NaN.
We recommend that th array size in the JSON data to be less than 1500 which can be achieved by setting -m parameter to be less than 1500 in your VCS configuration.