From ArchWiki
Revision as of 02:28, 11 June 2013 by Thoth (talk | contribs) (Multiple backends: added some more info about configuration)
Jump to: navigation, search

Varnish Cache is a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents.

Multiple backends

By default, varnish comes configured in /etc/varnish/default.vcl to use localhost:8080 as the only backend, default.vcl is called by the default systemd varnish.service file :

Description=Web Application Accelerator

ExecStart=/usr/bin/varnishd -a -f /etc/varnish/default.vcl -T localhost:6082 -s malloc,64M -u nobody -g nobody -F


systemctl enable merely makes a symlink to the default

$ systemctl enable varnish
ln -s '/usr/lib/systemd/system/varnish.service' '/etc/systemd/system/'

instead copy it and edit to increase malloc default.vcl etc:

$ cp '/usr/lib/systemd/system/varnish.service' '/etc/systemd/system/'

Also, the VARNISH_CFG file is not loaded on varnish instalation nor service startup. So in case you want multiple backends from a VCL file, you need to edit /etc/varnish/default.vcl with at least one backend and call:

$ systemctl restart varnish.service

or to reload

$ systemctl reload varnish.service

Manual VCL load

If the previous VCL configuration reload failed, try loading the VCL file manually:

  1. Connect to the varnish console:
    $ varnishadm -T localhost:6082
  2. Load the default VCL. Make sure it has at least one backend:
    varnish> vcl.load default /etc/varnish/default.vcl
  3. Make it active:
    varnish> vcl.use default
  4. Start the child proccess (optional):
    varnish> start