Question: Is it possible to maintain 100% uptime for my site?
Answer: Yes, it is possible to maintain 100% uptime. To maintain 100% uptime would require a significant investment in the web hosting setup. This setup would cost in the millions each year and would require contracts with dozens of different datacenter operators.
The site that would require 100% uptime would have to be hosted worldwide in every country that must have 100% uptime. Within each country the site would have to be hosted in more than more datacenter to make sure if there is any network disruptions that the site is still accessible.