Varnish Caching

Description

Complete WordPress Varnish Cache 3.x/4.x/5.x integration.

This plugin handles all integration with Varnish Cache. It was designed for high traffic websites.

Main features

  • admin interface, see screenshots
  • console for manual purges, supports regular expressions so you can purge an entire folder or just a single file
  • supports every type of Varnish Cache implementation, see screenshots for examples
  • unlimited number of Varnish Cache servers
  • use of custom headers when communicating with Varnish Cache does not interfere with other caching plugins, cloudflare, etc
  • Varnish Cache configuration generator
  • purge key method so you don’t need to setup ACLs
  • debugging
  • actively maintained

You can control the following from the Varnish Caching admin panel :

  • Enable/Disable caching
  • Homepage cache TTL
  • Cache TTL (for every other page)
  • IPs/Hosts to clear cache to support every type of Varnish Cache implementation
  • Override default TTL in posts/pages
  • Purge key based PURGE
  • Logged in cookie
  • Debugging option
  • console for precise manual purges

This plugin also auto purges Varnish Cache when your site is modified.

Varnish Caching sends a PURGE request to Varnish Cache when a page or post is modified. This occurs when editing, publishing, commenting or deleting an item, and when changing themes.
Not all pages are purged every time, depending on your Varnish configuration. When a post, page, or custom post type is edited, or a new comment is added, only the following pages will purge:

  • The front page
  • The post/page edited
  • Any categories or tags associated with the page

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. This plugin does not install Varnish for you, nor does it configure Varnish for WordPress. It’s expected you already did that on your own using the provided config files.

Inspired from the following :

  • https://wordpress.org/plugins/varnish-http-purge/
  • https://github.com/dreamhost/varnish-vcl-collection/

Screenshots

  • Settings admin panel
  • Console/manual purge admin panel
  • Varnish Cache Statistics admin panel
  • Varnish Cache configuration generator admin panel
  • override default TTL in posts/pages
  • integration example

Installation

  • You must install Varnish Cache on your server(s)
  • Go to the configuration generator. Fill in the backends/ACLs then download the configuration files
  • Use these configuration files to configure Varnish Cache server(s). Usualy the configuration files are in /etc/varnish. In most cases you must put the downloaded configuration files in /etc/varnish and restart Varnish Cache

Or use the provided Varnish Cache configuration files located in /wp-content/plugins/vcaching/varnish-conf folder.

You can also use the purge key method if you can’t setup ACLs. You must fill in lib/purge.vcl the purge key.

FAQ

Installation Instructions
  • You must install Varnish Cache on your server(s)
  • Go to the configuration generator. Fill in the backends/ACLs then download the configuration files
  • Use these configuration files to configure Varnish Cache server(s). Usualy the configuration files are in /etc/varnish. In most cases you must put the downloaded configuration files in /etc/varnish and restart Varnish Cache

Or use the provided Varnish Cache configuration files located in /wp-content/plugins/vcaching/varnish-conf folder.

You can also use the purge key method if you can’t setup ACLs. You must fill in lib/purge.vcl the purge key.

What version of Varnish is supported?

This was built and tested on Varnish 3.x/4.x.

Why doesn’t every page flush when I make a new post?

The only pages that should purge are the post’s page, the front page, categories, and tags.

How do I manually purge the whole cache?

Click the ‘Purge ALL Varnish Cache’ button on the “Right Now” Dashboard.

How do I manually purge cache?

Use the console. For example you can purge the whole uploads folder with the URL /wp-content/uploads/.*

Does this work with W3 Total Cache?

Yes it does. This plugin uses its own custom headers to communicate with Varnish and does not interfere with the heders sent by W3 Total Cache or any other caching plugin.

Varnish Statistics

Statistics need a special setup. More info on the Statistics tab on your WordPress environment.

How do I configure my Varnish Cache VCL?

Use the Varnish Cache configuration generator. Fill in the backends/ACLs then download your configuration files.
Or use the provided Varnish Cache configuration files located in /wp-content/plugins/vcaching/varnish-conf folder.

Can I use this with a proxy service like CloudFlare?

Yes.

What is logged in cookie?

Logged in cookie is a special cookie this plugin sets upon user login. Varnish Cache uses this cookie to bypass caching for logged in users.

This is a small step towards securing your site for denial of service attacks. Denial of service attacks can happen if the attacker bypasses Varnish Cache and hits the backend directly.
With the current configuration and the way WordPress works, this can still happen with POST/AJAX requests.

Available filters
  • vcaching_varnish_ips – change the IPs set in Settings
  • vcaching_varnish_hosts – change the Hosts set in Settings
  • vcaching_events – add events to trigger the purge
  • vcaching_schema – change the schema (default is http://)
  • vcaching_purge_urls – add additional URLs to purge

Reviews

Age 0 problem in header solved by this plugin

A great way to test if Varnish is truly and totally working on website is verifying if the “age” value is increasing in page’s header when checking the website using a tool like Chrome’s Developer Tools.

http://d33v4339jhl8k0.cloudfront.net/docs/assets/5415e7bfe4b01e2a68fe8243/images/58058721c697915a23d7a629/file-a9Lg9golUw.jpg

I was having a problem where this age value in header was always 0 which meant that Varnish was not caching pages properly.

After testing different Varnish configs from Google, I was never able to make it work. After installing this plugin, this age value is now increasing.

It integrates perfectly with wordpress. However, the purge option was not working properly on my website and the age value (which was now increasing thanks to this plugin) was not being purged when purging Varnish using this plugin, therefore, it was constantaly increasing without rolling back to 0. Nevertheless, this purge problem was also resolved after installing the “Varnish HTTP Purge” plugin.

Awesome!

By far the most advanced plugin form managing varnish cache from WordPress.

Read all 7 reviews

Contributors & Developers

“Varnish Caching” is open source software. The following people have contributed to this plugin.

Contributors

“Varnish Caching” has been translated into 1 locale. Thank you to the translators for their contributions.

Translate “Varnish Caching” into your language.

Interested in development?

Browse the code, check out the SVN repository, or subscribe to the development log by RSS.

Changelog

1.6.7

  • use sys_get_temp_dir() to address open_basedir restictions to /tmp. thanks @maltfield

1.6.6

  • no more SSl auto detection. If you use SSL with Varnish use the option ‘Use SSL (https://) for purge requests.’
  • there are cases where the website uses SSL, but the Varnish servers do not

1.6.5

  • added sslverify set default to false to wp_remote_request. thanks @Jules81

1.6.4

  • fixed php notice

1.6.3

  • added SSL to schema filter. thanks @Jules81

1.6.2

  • fixed purge_post empty 2nd param

1.6.1

  • Do/do not purge when saving menus option
  • fixed bug showing multiple Truncate message activated ...

1.6

  • Varnish 5.x support

1.5.5

  • fixed ob_end_flush error in wp-admin while debug is on. thanks @samlangdon

1.5.4

  • improvements to Varnish configs like websocket support, remove the Google Analytics added parameters, strip hash, remove unnecessary cookies. thanks @pavelprischepa

1.5.3

  • hardcoded on/off VCL Generator, filters added to readme

1.5.2

  • added AMP URL purge

1.5.1

  • fixed PHP notices
  • tested with 4.6

1.5

  • Purge from Varnish post/page action link
  • removed 10 chars logged in cookie restriction
  • code cleanup/some wp coding standards
  • vcaching_varnish_ips filter
  • vcaching_varnish_hosts filter

1.4.3

  • Truncate option added for too many ‘trying to purge’ messages. Added check for ZipArchive class to download VCLs.

1.4.2

  • Bugfix release. Replaced home_url with plugins_url to show VCaching image

1.4.1

  • Do not cache static files on admin domain

1.4

  • Varnish Cache configuration generator
  • added logged in cookie. This replaces the logged in admin/user based on WordPress standard cookies to bypass caching
  • moved backends to conf/backend.vcl
  • moved ACLs to conf/acl.vcl
  • updated VCLs. If you are using 1.3 VCLs should upgrade to 1.4

1.3.3

  • support for Varnish 4

1.3.2

  • bugfix displaying a single server stats

1.3.1

  • better varnish statistics, generated by varnishstat

1.3

  • varnish statistics

1.2.3

  • wordpress 4.4 compatibility
  • Romanian language file

1.2.1

  • wp cli

1.2

  • console for precise manual purge

1.1

  • Play nice with W3 Total Cache

1.0

  • Initial commit