Varnish Cache (VC), and Varnish Enterprise (VE) categorized as Reverse Proxy
or HTTP/web accelerator
, are standalone products. They can operate independently without any controller/monitoring node like Varnish Controller and VCS. Customers must supply their own version of the Varnish Configuration Language (VCL) file to utilize the capabilities of VC and VE.
Varnish Custom Statistics (VCS) produces real-time aggregated statistics from a group of caching servers. The statistics produced are grouped according to VCL-defined keys and presented in time series. The vstatdprobe is only pre-installed in VE.