Varnish

Description

High-performance HTTP caching.

Components

  • Varnish

Configuration

  • The file /etc/varnish/default.vcl is provided with a template. It can be edited/replaced by service users. Please note that the default Varnish incoming port is 8008. You need to reflect this in your webserver config to use Varnish.

Interaction

  • Service users may restart Varnish after configuration changes with sudo /etc/init.d/varnishd restart.

Monitoring

  • We monitor that the varnishd process is running and the varnishd port is open.

Debugging

Varnish may refuse to start when provided with an invalid VCL configuration without giving much information. In this case it may be helpful to [1]:

  • start Varnish with a known good configuration
  • attach to varnishadm via varnishadm -T 127.0.0.1:6082
  • load the new config with vcl.load error <path_to_your_vcl>
[1]As seen on StackOverflow.