My Web hosting company guarantees 99.9% uptime. What does that really mean? Thanks, Dale.
Dale, that’s a great question and one many people don’t really consider. To begin to understanding this we need to know what is meant by uptime. Uptime is based upon the server status. It has nothing to do with network connectivity between your or your customers and your Web site. Simply put … the only thing that can be guaranteed is that the server will be up and running.
Uptime guarantees are over the period of one calendar year. So, that means of 525,600 minutes in a standard year, your site can be down 525.6 minutes or 8.75 hours will meet the 99.9% uptime guarantees offered by some companies. There are companies whose guarantee is 100%, but to be honest there is no way they can guarantee any of these rates for the delivery of a Web site.
Common factors affecting the delivery of your Web site are DNS issues, router issues, ISP issues and HTTP server software. In a shared hosting environment any other client on your server can cause the HTTP server software to go down. The worst situation is when your ISP updates their DNS records on a slower schedule than we might prefer. Some ISPs update their DNS records every two weeks or even longer.