What is Web Hosting Server Uptime?
In very simple terms, ‘Uptime’ is the amount of time that a web server (and the web sites hosted on it) are up and running. Server uptime is generally a good indication of how well a web hosting company maintains and monitors it’s web servers. The better maintained and monitored a web server, the better uptime a server will more than likely have. So, if a web hosting company has a high uptime, that means their servers stay up and running regularly and reliably.
Most web hosting companies offer server uptime guarantees that are based on a percentage of time. For example, a 99.9% uptime guarantee or something similar.
The calculation to determine what a company’s uptime server guarantee amounts to is: the total number of minutes in a month X (100 – the uptime guarantee percentage amount)/100.
So, if a company has a 99.9% uptime guarantee, the maximum amount of time that they estimate your web server & web site could potentially be “down” is 43.2 minutes per month. Anything over and above that number will usually be reimbursed to you.
Here is the 99.9% Uptime Guarantee calculation:
30 days in a month X 24 hours a day X 60 minutes an hour X (100-99.9)/100 = 43.2 minutes maximum downtime per month
Of course, this doesn’t mean that your web site (and the web server your website is hosted on) will be down for 43.2 minutes each month. Rather, it means that your hosting company guarantees that it will be up 43,156.8 minutes out of the total 43,200 minutes each month and (depending on the company’s terms) may reimburse you for any downtime above and beyond that amount each month.