Solved: Varnish 4 “Internal Server Error 500”

by Danila Vershinin, February 27, 2016

Why Varnish returns “Internal Server Error 500” Once you done writing your VCL for Varnish 4, you may not be aware that it silently fails with 500 Internal Server Error for some requests. Most likely, the reason is client workspace overflow. When you run varnishlog and watch for requests, you will see: “LostHeader” and “workspace_client […]


Generate CSR for SSL certificates FAST

by Danila Vershinin, January 13, 2016

This handy Bash script will help you to quickly create Certificate Signing Requests for your SSL certificates


Varnish static files stream

by Danila Vershinin, November 19, 2015

Caching large static files in Varnish is not efficient for storage. Let’s use streaming in Varnish 4!


Configure Swap file on CentOS

by Danila Vershinin, October 17, 2015

When physical RAM is not enough for the system to handle its routines, Swap comes to the rescue. Let’s find out how to configure swap file on a CentOS VPS.


Varnish: do we have to cache static files?

by Danila Vershinin, October 14, 2015

Varnish is a great caching solution to speed up any website
But does it need to cache static files which are already fast to deliver?


Fix slow SSH and DNS in CentOS 6

by Danila Vershinin, September 6, 2015

Slow SSH can be a pain to work with. We have insight on the causes of slow SSH as well as quick fixes to make it faster


Server Email Setup

by Danila Vershinin, July 14, 2015

Setup email on your server without too much hassle!


Reset MySQL root password in CentOS 6 / 7

by Danila Vershinin, November 7, 2014

Change MySQL root password or reset it easily with these simple SSH commands


FirewallD FTP rule: allow access to FTP service in CentOS 7

by Danila Vershinin, October 8, 2014

Sometimes you have to use tricks to accomplish a task. Even a trivial task might require special workarounds. Let’s enable access to FTP service on a CentOS 7 which comes with FirewallD as default firewall component in operating system. You might be fine without the workaround, but if you have an issue – you will have to use it.



by Danila Vershinin, October 2, 2014

Caching is the most essential piece of the performance puzzle. What is the fastest cache storage? Of course, it’s RAM. Why not use the RAM of all available servers and put it up as single distributed cache storage for your busy internet application. Meet Memcached – it’s there, it’s free and it will do the task.