Uptime in the hosting world refers to the percentage of time your provider is accessible via the internet. Some hosting providers offer a 99% uptime guarantee while others offer a 99.99% and on rare cases you will see a 100% uptime guarantee. What you have to determine is whether this is for server on time or network on time. Some providers will state that they offer the best uptime in the business yet you can never get to your site. A ping will show that the server is running, but the thing they don't guarantee is their network and the ability to get to your actual domain. You will need to be mindful of statements such as "Downtime is defined as our network equipment or web hosting server being down. We do not control the Internet and therefore do not guarantee your ability to access your site." While this statement is somewhat true, you really just need to research your host before hand.

If you were to think of the uptime percentages offered by providers, over a given year you would have the following downtime:

* 100% - 0 hours 0 minutes
* 99.9% - 8 hours 46 minutes
* 99.5% - 43 hours 50 minutes
* 99.0% - 87 hours 39 minutes
* 98.0% - 175 hours 19 minutes

Keeping tabs on your web site uptime

There are a number of ways to monitor your web site uptime. There are services that provide full monitoring, software that you can install locally that will go out a check different services to ensure they are running, as well as some free scripts that you can use such as Nagios for example that you can install on a completely different server to monitor mulitiple servers and clusters. Some of these are expensive services and well, some like I stated are free. Contact your provider for any other recommendations for monitoring services.

If you are running into a large amount of downtime with your host, call their technical support team. Keep in mind that it may not even be the server. Factors such as firewalls can hinder you from getting to your site or hosting providers server. Firewalls both locally and remotely can come into play here. Problems such as this may be troubleshooted by your hosting provider if their staff are aware of this types of issues.