Downtime in the Cloud
Yesterday my website went down a few times. As it is hosted on Heroku it is always a possibility that it goes up and down without me being able to fix this. Heroku in turn is using Amazon EC2 and is therefor vulnerable to any problems occurring at their datacenters.
Amazon apparently had some problems with their EBS service which caused Heroku to get some hiccups. There are several great posts that have discussed whether or not to trust cloud services or to build own datacenters. To be secure in the cloud I think you should, as with everything, spread the services on different providers. Putting all your money in one stock is risky business, spreading the money in several stocks will make you more resistant to failure if one of the stocks plummets.
Of course my website is not that critical and there is now way that I state that it should have 100% uptime (or even five nines). 98-99% is good enough for me. 98% will be about a week of downtime, hopefully this would not occur at the same time. If I had a service that would lose money each time it went away from the Internet it would be a completely different matter.
I would recommend these posts about the Amazon issues and availability: