What is Varnish Cache and How Does it Perform?

If you have a content-heavy website, consider using Varnish Cache to speed it up.

The Varnish Cache tool is a HyperText Transfer Protocol (HTTP) accelerator that is used to speed up content delivery, especially needed for content heavy websites and APIs. Also called as a web accelerator, an HTTP accelerator improves web access time and can be installed either on the client computer or tablet or can be put-upon any software. Unlike other proxy servers that work on protocols like FTP, SMTP, etc., Varnish focuses on HTTP exclusively.

Varnish Cache is used by the top websites of the world such as Facebook, Reddit, Wikipedia, The Guardian, The New York Times and several other publications. These publishers use Varnish to speed up their content delivery to the users.

History of Varnish Cache

Varnish launched its first stable version in 2006. Since then, successive improvements were introduced in 2008, 2011, 2014, 2016 and last in 2018. This product was developed for the digital team of the Verdens Gang which is a Norwegian newspaper. The main developer of this exciting  product is Denmark’s Poul Henning Kamp while management and infrastructure support is provided by the Norwegian company, Linpro. Later, this product was spun off as a separate company and today operates under the brand name, Varnish Software.

Performance Metrics

Varnish can speed up content delivery several hundred times. While doing so, it monitors the following factors:

1. a) Client metrics like client connections and requests
2. b) Cache performance like hits and evictions
3. c) Thread metrics like thread production, queues, and failures.

In addition, Varnish Cache also monitors the back metrics like the failure and success rate and the health of backend connections.

Advantages of using Varnish Cache

1. By speeding up content delivery, Varnish improves the performance of your website significantly.
2. Low consumption of server resources
3. CPU consumption is low
4. SEO ranking improves
5. Varnish Cache offers full site optimization

How does this Cache work?

1. Install this Cache in your website
2. Client end requests to access the URL ‘ http//example.com’
3. HTTP listens to this request on port 80. This request travels through the network and fetches the DNS and finally fetches the server as well.
4. Once the server is fetched, the website is delivered at the client end in the browser.
5. If the client requests the same URL, content is delivered from the Varnish caching system.

By installing the Varnish Cache, your website delivery time will reduce from 3-5 seconds to 1-2 seconds. Go for a cloud hosting provider who uses this Cache in his package for improving your website performance.

In addition, Varnish Cache does the following things:

1. Decompression and Compression of Gzip
2. It tests support for Steady Stockpiling
3. HTTP Gushing, Pas and Get.
4. Varnish Cache also offers plugin support with Varnish Modules or VMODS.
5. Load balancing with a round robin and random director.

Load balancing is a process by which your website load is redistributed between web servers to optimize your website performance.