How to clear the Varnish cache

Purge the Varnish full-page cache on TurboStack with tscli varnish clear - when to use it, the application alternative, and what to expect afterwards.

Varnish serves a full-page cache of rendered HTML. Clear it when visitors could be seeing stale pages - for example right after a deploy or a content change that the application did not purge on its own.

Before you start

SSH access to the host as the application's system user - see SSH access.
Varnish enabled on the application - see Configure Varnish.
A quiet moment if you can: the whole host serves from the application until the cache refills.

Clear the cache with the TurboStack CLI

Connect over SSH and run:

tscli varnish clear

This empties the entire full-page cache for the host. The next requests are served from your application until the cache refills, so expect a short performance dip.

Note

tscli varnish clear empties the cache; tscli varnish reload is different - it validates and reloads the Varnish Configuration Language (VCL) after you change a rule (see Exclude pages from the cache).

Prefer your application's own purge

A full clear is a blunt instrument. Applications that integrate with Varnish (for example Magento) purge only the pages that changed when you update content, which is far less disruptive than emptying everything. Use tscli varnish clear when you need a clean slate, or when the application cannot purge on its own.

After clearing

The first hits are slower while Varnish rebuilds the cache. Warm the important pages by visiting them, or let your sitemap or a crawler do it, before judging performance.

Apply and verify

The clear is immediate. The first request for a page afterwards comes from the application and shows Age: 0. The second request shows a growing Age, which proves the cache is filling again:

curl -sI https://www.example.com/ | grep -i age

If it did not work

A page that still looks stale with Age: 0 is not served by Varnish at all. The old content then comes from the OPcache, the application's own cache, a browser cache or a Content Delivery Network (CDN) in front of the host. A page whose Age never drops was not cleared - run the command again as the right system user and read its output. See Why is my site slow?, or contact support.

Configure Varnish
Exclude pages from the Varnish cache
What is Varnish?
Clear the Redis cache
Why is my site slow?
TurboStack CLI - tscli varnish clear and tscli varnish reload