What is server uptime and what does it mean to you? Our friends at wikipedia define uptime as "Uptime is a measure of the time a machine has been up without any downtime." Or in other words, how available is your website... Downtime basically being any period of time your website is not available and up for public usage.

So what does this really mean to you? Why should you care aboue uptime? There are really three basic reasons:

1. You want your visitors to find your website open for business: If your website is offline when people are looking is like not answering your phone when a customer calls - imagine not even having an answering machine or voicemail, the phone just rings. It leaves the person wondering if you're still in business....
2. Search engines actually penalize your website ranking when your website is offline when they try to search it. So all of that effort you put into ensuring your website is showing up high on Google is now being waisted by your website being offine. ^Ref
3. Large downtime should leave you questioning the quality and reliability of your provider.  If they have large unexpected downtimes, then it may indicate a greater problem is looming and your website might go down for even longer periods of time, instead of hours, it might be days next time. Proper preventative maintenance can significant help your uptime.

Having good uptime is very difficult, and what is generally considered "google" entry level uptime is 99% uptime, which may sound really good, until you consider that 99% of a year is over three days of your website being unavailable. And typically this is at the worst possible time for you, such as the start of the week or after a product launch! A better quality hosting company may offer 99.9% uptime, which is commonly referred to as "3 nines"... For this increase in available, which is actually 1/10 the downtime, so instead of 3 days, its around 8 hours of downtime per year. Imagine what it takes to keep something running around the clock 24x7 with only 8 hours per year - that is less than 1 hour per month... Some conservative estimates suggest that it costs about 10 times as much to provide 99.9% uptime compared to 99% uptime...

However excellent, top tier webhosting companies, including your Redding based ProactiveWeb, provides 99.99% uptime, or about 4 minutes of downtime per month! And that, as some suggest is another 10 times the cost as 99.9% uptime.

Yet it doesn't stop there... Here is the little secret of many hosting companies, including many of the biggies, or other popular hosting companies... Their uptime statics and guarantees exclude:

• Scheduled maintenance
• Performance issues which only affect part of your service (such as web only, but not e-mail; or ftp but not web; etc)
• "Unlimited" plans which limit the number of concurrent connections, and when that number is exceeded, they deny new visitors (which appears as a website down to end users)

References: [1] [2] [3]

We don't believe it is in the interest of our clients to provide those figures because they are highly skewed. It is relevant to understand the total downtime both scheduled and unscheduled. It is great when a hosting provider avoids large unplanned downtime, but even planned downtime still causes problems to your customers and your search ranking. For this reason we focus on total uptime, and our latest measurement (September 2012) was 99.988% or if you reasonably round up...  

99.99% uptime INCLUDING scheduled downtime and maintenance

That figure is the prior 12 month average, including monthly reboots for Microsoft or Red Hat security patches.

What should you be asking your current provider?

1. How often do you perform preventative maintenance including security updates? (should be monthly or at the very furthest, quarterly)
2. What is the total availability (uptime) of the webserver which you are going to be placed on, including the downtime caused by maintenance and reboots, over the prior year?

If they cannot provide those figures or they are not at least 99.9% uptime, then you should consider moving your website to a higher quality hosting company. That doesn't necessarily mean that it will cost you more each month... however by not changing providers, you may be costing your business in customer reputation and search engine ranking... neither of which are easy to regain.