A website is housed on what is called a website host or a computer in a data center (rather than a computer under your brother-in-laws bed, ew!) that serves the website to the internet. A site that is “down” is as good as not having a site at all – no visitors, no traffic, no revenue, nothing – zilch. Because of this, a very high uptime guarantee percentage should be your top, or at the very least, major criterion when choosing a host.
99.9% uptime is currently the industry standard for most hosting companies that service the average Joe/Jane on the street. So what does that actually mean in terms of actual hours and minutes? It’s a rather simple calculation really.
The total number of minutes in a month x (100-uptime%)/100
= 30days x 24hours x 60min x (100-99.9)/100
= 43200 x (0.1)/100
= 43.2 minutes (max downtime).
So, if it is 99.9%, it means your website should not be down for more than a total of about 43.2 minutes in a month. Mind you, the total number of minutes in a month is about 43200 minutes or 720 hours. So, 0.1% of downtime is actually very minimal. Out of this much time, your host should only down your site for a max of 43.2 minutes – whether it is for maintenance work, reboot, troubleshooting (because some monkey shares the same server as you and ran some mass emailing program/malicious script that cause CPU usage to go red ?), change of failed hardware etc.
This does not mean that your site will be down for 43 minutes every month. That figure is actually the longest or maximum down time. That’s not a lot of time unless you’re in the middle of a massive launch and you’re bleeding money because your potential customers are unable to get to your website. Some good hosts might actually give you 100% uptime for months in a row in reality – even though they state 99.9% for the guarantee that they give. These are hosts that take care of their CPU / RAM / executable file security etc – overall server environment properly.
Who tracks this? Well hopefully, the hosting company that you are contracting with is tracking this because they will be able to determine the cost effectiveness of the hardware that they are using so that they can make intelligent decisions regarding their own hardware maintenance costs based on this and other information. In theory, you can ask for your money back each time that they don’t honor their 99.9% uptime guarantee. They don’t freely give out money when they miss the mark, you need to ask for it. How would you know they didn’t miss the mark? You would need to track this information. Hosting companies are literally banking on the fact that most folks will say, “Ain’t nobody got time for that!” at this point. They’re right, most people (virtual assistants, online business managers, business owners) don’t have time for that. Most website developers who are worth their salt will write a computer program to track that information for you.
Some hosting services exclude normal maintenance time from this uptime guarantee and you will want to watch for this.