Varnish Cache comes with a set of parameters that affects behaviour and performance. Parameters are set either though command line arguments to varnishd or at runtime through varnishadm using the param.set CLI command.

We don't recommend that you tweak parameters unless you're sure of what you're doing. We've worked hard to make the defaults sane and Varnish should be able to handle most workloads with the default settings.

For a complete listing of all parameters and their specifics see List of Parameters.