Speed Up Your Magento2 Site with Varnish: A Step-by-Step Guide

1. Installing Varnish

In case you also do not have Varnish, you will need to follow the instructional section on how to Install Varnish before we can continue.

2. How to place Magento2 behind Varnish

Here we discuss how to configure your Magento2 behind Varnish. The Magento2 admin states that the built-in application cache is not recommended for production use, but that does not mean that Varnish is already configured. Varnish needs to be installed and the configuration file suitably configured and deployed.

We assume that you have Magento2 installed and running on your backend servers and that your server is a Debian-based Linux server.

Configuring Magento

1. Visit the Magento2 admin page and go to:

• > Stores
• > Advanced
• > System
• > Full Page Cache

Here switch caching application to Varnish

This is what the Magento2 mdmin page should look like:

Image courtesy: Magento Site

2. Configuring for Varnish

• Under the Additional section, find a button for exporting the ready-made configuration file for Varnish 3 or 4. We recommend you use Varnish 4, as earlier versions are no longer supported.

Click on::

-> Export VCL for Varnish 4 This is usually named varnish.vcl

Place the file in a Varnish folder for configuration (any place that is safe for you).

• Next, to add Varnish repository, follow the instructions at Install Varnish

3. Testing your setup

Now check if your services are up and running:

$ ps -e | grep 'apache2|varnish'

If you receive outputs like the ones below:

1143 ?        00:00:03 varnishd
1148 ?        00:00:17 varnishd
1366 ?        00:02:02 varnishlog
1591 ?        00:00:01 apache2
11743 ?       00:00:10 apache2
11744 ?       00:00:10 apache2

Congratulations! You have your services running on the backend.

Now we need to check the Magento2 frontend: As you may have already noticed above, there is a varnishlog process running as well.

3. Restarting services after making changes

sudo systemctl restart varnish.service

sudo systemctl restart apache2.service

4. Basic caching

Varnish does not cache cookies or their headers. But some cookies are marked as safe by the Magento site. Therefore it is recommended to remove or ignore these cookies so that Varnish can cache anything.

An example, such as the following, will help to unset/remove unwanted cookies.

Update your default.vcl with this code or a similar code of your choice.

Under the vcl_recv add the following code.

Warning: Make sure to add the code below the default code given for vcl_recv

sub vcl_recv {
  if (req.http.cookie) {
    set req.http.cookie = ";" + req.http.cookie;
    set req.http.cookie = regsuball(req.http.cookie, "; +", ";");
    set req.http.cookie = regsuball(req.http.cookie, ";(COOKIE1|COOKIE2|COOKIE3)=", "; \1=");
    set req.http.cookie = regsuball(req.http.cookie, ";[^ ][^;]*", "");
    set req.http.cookie = regsuball(req.http.cookie, "^[; ]+|[; ]+$", "");

    if (req.http.cookie == "") {
      remove req.http.cookie;
    }
  }

5. Excluding certain URLs

Not all URLs should be cached. Especially not in sites that deal with personal information such as credit cards or financial details.

if (req.url ~ "magento_admin|magento_login") {

return (pass);

}

6. Extended caching

There is a subroutine called vcl_fetch which is by default set to 120 seconds as can be seen. You can extend this caching value by:

sub vcl_fetch {
       set beresp.ttl = 5s;
}

This sets the TTL to 5 seconds, making Varnish pick up changes every 5 seconds. Add this subroutine right below the backend default.

However, there is a downside to short TTL values in that they increase the load not only on the backend servers but also on frontend servers. Of course this gives you a better control over your cache, but it also increases overheads, such as network traffic, slower response times, which diminish the whole purpose of Varnish.

Decreasing TTL values is not a good solution for high-traffic servers. Varnish has a better solution for that.

7. Specific TTL-based caching

Varnish creates a TTL value for every object in the cache. The most effective way of increasing a website’s hit ratio is to increase the time-to-live (TTL) of the objects.

8. Go further

If you are interested in Varnish, you can always give Varnish Plus a go with a free trial. You can capture real-time traffic statistics, create a paywall for premium content, simultaneously work on administration across all Varnish servers, record relationships between web pages for easy content maintenance, detect devices used for browsing, accelerate APIs and more.

Check out the links below to take your Varnish-Magento site to new performance heights.

9. For more guidance

You can always refer to the Configure and Use Varnish at the Magento site.

To see the guide on installing and configuring Magento with Varnish on web servers, please look at here.

If you are interested in trying out an installation, download Marko’s Vagrant Box marko_magento2github. His installation used nginx with Varnish and Magento. You can also read more about in Marko’s blog post about placing Magento2 behind Varnish marko_magento2post.