Concepts used in the VAC

A cache group is a collection of Varnish Cache servers that have identical configuration. Attributes on a cache group includes:

  • One or more Varnish Cache servers
  • Active Varnish Configuration Language (VCL) file
  • Homogeneous parameter configuration across all servers in a group

A VCL file is a configuration file which describes control flow when Varnish Cache handles a HTTP request. VAC distributes and store VCL files for you.

A parameter set is a list of Varnish cache parameters. A parameter set can be applied to one or more cache groups simultaneously, as long as the cache groups all consist of cache servers of the same Varnish Cache version.

VAC ships with a JSON-based RESTful API. All actions performed via the user interface can be replicated with direct access to the API. This includes fetching all real-time graph data.

Logging in

The default user is “vac” and the default password is “vac”. Please change the login password the first time you log in.

You can access VAC on http://server_hostname/ .


The VAC as three types of roles both for the UI and API.


  • Create/edit/deploy/remove/delete VCL and parameters
  • Issue bans
  • Add and remove caches to cache groups.
  • Can create/edit/remove/restart groups.
  • can create/edit/remove users. Change user details, roles, and assign users to groups


  • Has all rights as Admin except adding group, assigning group, adding users, updating other user’s details and roles.
  • Can change its own user details.


  • Can see the list of caches, and check the monitoring of the groups that is assigned to the role.
  • Can’t execute any write/change operation.