Yesterday lightning strikes in Dublin took down major cloud computing data centre hubs used by both Amazon and Microsoft.
Is this a problem for Cloud Computing? Certainly it does unsettle anyone who is thinking about moving to the cloud, but let's think about that for a minute. Major events can take down data centres anywhere, cloud or not. If you are hosting your existing infrastructure in your office or in a data centre then you are still vulnerable to lightning strikes and it's your job to handle the recovery. If you are hosted in the cloud then at least you have someone there to help. In the case of Amazon the lightning strike took down one of the two Availability Zones, the other still continued to work. In other words the Availability Zones did what they were designed to do and if your application or service was designed to run across two Availability Zones you were okay. In short, the "Cloud" worked.
If you are using a SaaS provider then they should handle all of this engineering for you. The question you need to ask them is how they handle a data centre failure?