Downtime in IT is when a piece of equipment (such as a computer or other device) is not functioning or can’t function in the way it was designed. Downtime is a subjective concept and can be easily defined as being the opposite of uptime. Usually, we use the term “downtime” to refer to periods when a system, device, computer or internet website is unavailable.

Internet website downtime means that the end-user cannot:

  • access the website,
  • perform and complete the main task on the website

Nowadays, downtime is more complex than we believed even a few years ago. Website downtime (opposite to website uptime) is when a website is unavailable online or can’t function well enough for end-users to complete the main task. For example, the primary user task in e-commerce is to add to the basket and buy products or services. Another example from the accommodation/hotel industry is that users can choose and book a room. When the user can’t perform these tasks on the website (even if the user can access the website) it is referred to as downtime.

The cost of website downtime is a financial estimate intended to show the losses and additional costs generated by a website or service during downtime.

Common reasons a website might be down are:

  • human error – e.g. wrong DNS entry on the server, error in PHP causing disconnection with database, any other error caused by people
  • equipment failure – e.g. server or network breakdown, power outage and any other reason caused by the hardware
  • malicious attack – e.g. malware infection, Distributed Denial-of-Service (DDoS) attack, DNS (Domain Name Servers) cache poisoning, hijacking or redirection, any other malicious activity causing website downtime
  • catastrophic accident and natural disaster – e.g. fire in the server room (read about this in our article “Fire in the server room – why do you need independent backup“)
  • traffic overload – it is funny that success can be a failure; if you expect massive traffic, first check that your server can deal with it.