INTRODUCTIONVarnish is a high-performance HTTP accelerator. Acting as a reverse HTTP proxy, it appears as an ordinary server to its clients. It excels at storing static files in memory to decrease the server response time and hence improves page load times for a website’s users. So, it is mostly used as an HTTP/web accelerator. In the real world, it typically boosts the content delivery by 300-1000 times. However, that is not it. Let’s look at some of its key features.
FEATURESVarnish is packed with several useful features:
- It is open-source
- It can be configured using the flexible Varnish Configuration Language (VCL)
- It can act as a Single Sign-On gateway
- It can defend servers from low-intensity DDoS attacks
- It can act as an L7 HTTP Router as well as a web application firewall (WAF)
BENEFITSVarnish offers the following benefits:
- Varnish is written in C and delivers high-performance while being bound only by network speed.
- Open to customizations. Varnish being open-source, it opens the doors for all sorts of customizations that you can do to implement Varnish your way. Varnish open-source code can be tweaked to suit your requirements and make it even more powerful.
- Instant purging that helps instantly remove cached dynamic content.
- Proper documentation that makes it easy to get started.
- Reverse proxying that caches relevant static content and lets dynamic content pass through without any noticeable performance impact.
- Varnish comes with several useful tools that make your job easier by helping you get the details that you are looking for quickly. For example, if you want to look at statistics, logs, access logs, hit vs. miss histogram, or if you want to debug, Varnish has all the tools inbuilt.
- Real-time data monitoring of content empowers you to observe and analyze the data using open source dashboards. Varnish being popular, most monitoring tools provide support for monitoring Varnish.