A major outage at Amazon’s northern Virginia cloud computing data center reportedly knocked dozens of Web sites offline today, April 21, but new ticket...

A major outage at Amazon’s northern Virginia cloud computing data center reportedly knocked dozens of Web sites offline today, April 21, but new ticket exchange Ticket Evolution was not affected, according to a company spokesperson.

The exchange, which utilizes Amazon’s cloud computing services, has not experienced any downtime today, when one of Amazon’s data centers crashed in the wee hours this morning.

“[There have been] no problems and there has not been any spike in customer issues at all. As a matter of fact it’s kind of a slow day in broker land,” the Ticket Evolution spokesperson said.

The Amazon Elastic Compute Cloud outage reportedly affected the popular Web sites Foursquare and Reddit, and a division of Salesforce.com, among dozens of others, bringing down some sites for hours. Amazon said the issue involved “instance connectivity, latency and error rates,” and the company expected to have the situation resolved today.

Cloud computing allows companies to save on storage costs and easily access information from multiple locations because data is stored on remote servers. Ticket Evolution is the first large-scale ticket exchange to build its system from the ground up to utilize cloud computing services, and its membership has grown significantly over the past several months.

However, the widespread nature of the outage, which Amazon was still frantically working to fix this afternoon, called into question the reliability of some computer cloud models.

“Customers need to start asking tough questions and not assume everything will be taken care of in the cloud, because it will not,” Forrester Research analyst Vanessa Alvarez told Bloomberg. “They shouldn’t be counting on a cloud service provider like Amazon to provide disaster recovery.”

In an interview with the Wall Street Journal, she added, “Amazon’s taking the hit today because they’re the poster child, but outages aren’t anything new and unfortunately they’re going to continue to happen.”

Despite the concerns, the overall market for cloud computing services is expected to grow to more than $100 billion by next year, up from nearly $70 billion in 2010, according to the Journal, citing figures from technology research company Gartner.