Posted by Ray Majoran
Every once in awhile we have a situation where, because of unforeseen circumstances, we have to reboot a server or install a critical patch; or something merely goes wrong and we have to reboot a web service. Most of the time, we are able to defer these situations to the wee hours of the night when most people won’t even know they took place. If we need to install updates that will result in more than 5-10 minutes of downtime, we let our clients know so that they can be prepared for it. It’s standard hosting practice.
That said, like many other hosting providers, we strive for 99.9% uptime; the actual number that we hit is actually higher.
When we tell our clients that we strive for 99.9% uptime, they are astonished. “Wow, that is amazing”, they say. However, we still have the odd client that lays into us if we go down for 5 minutes due to unforeseen circumstances.
So, in order to clarify, here’s what 99.9% uptime looks like if you do the math:
If we are to hit 99.9% uptime that would mean (based on a 30 day month) that we need to be up for 43,157 minutes out of 43,200 minutes per month, leaving us 43 minutes per month of potential downtime. No hosting company wants 43 minutes per month of downtime; believe it or not, we’ve had months with 0 minutes of downtime. But downtime does happen.
Any company that tells you that they are up 100% of the time is lying to you. Even Amazon.com, with their massive cloud computing structure, goes down.
“Amazon's data storage service was down for several hours on Friday morning, leaving businesses that rely on the service offline.” [PC World News, February 2008]
At the end of the day, hosting companies strive for perfection. However, computers don’t always act the way that we’d like them to, regardless of how many redundancy practices we put into place. I’d like to think that one day there will be a hosting practice that will be perfect – no downtime – but until software and computers stop being built by humans, it probably isn’t going to happen any time soon.