Optimizing your own web hosting with Varnish Cache can be very useful in the face of an increase in its complexity and the number of web visitors. However, the implementation of the software is not recommended for all types of web projects. To get a better overview, we have summarized the pros and cons of Varnish:
| Advantage: || Disadvantages: |
| ? Faster loading speed thanks to content storage in memory || ? For those systems that do not interpret ESI, Varnish Cache does not offer any optimization possibilities |
| ? Load balancing on the server || ? Increased complexity and susceptibility to errors |
| ? Edge Side Includes Markup Language || ? There is no support for TLS / SSL, i.e. for HTTPS |
| ? The operating system stores content on the server's hard drive || ? Complex installation and configuration processes. Requires experience |
| ? Load balancing with the round robin method || ? Only for Unix operating systems |
| ? Flexible configuration options thanks to VCL |
The above comparison shows that Varnish Cache is the appropriate complement to existing caching functions (on clients and web servers) when working with a web application that allows interpreting the ESI markup language. On the other hand, the installation and configuration of Varnish Cache, including ESI tags, is not easy. Also, because Varnish does not support TLS / SSL connections, it is necessary to use another proxy server to ensure secure transmission.
Those projects where Varnish Cache is configured correctly, as well as their ESI tags, will speed up their loading speed much more than using conventional caching methods. Consequently, this software will greatly reduce the loading time for your visitors, which in the long run will mean a significantly higher conversion rate. In the same way, you will automatically benefit from a better ranking in search engines and a reduction in the load on your web server, which will no longer be solely responsible for the processing of incoming connections. In particular, Varnish Cache is a program used mostly by operators of online stores and dynamic web pages with a great variety of content..