Finally, most Web applications, particularly those that that involve rich media, will benefit from a CDN (content delivery network), which dials down user frustration -- globally, depending on the number of edge servers on the network. Here again, some providers have their own vast CDNs, and some partner with the likes of Akamai, but the bottom line is the ease of setup and the actual reduction in latency.
Database and app dev services
You can upload almost any database software you like to the cloud -- but it's much better to have database services maintained by the IaaS provider and ready to deploy. SQL database services are common, with MySQL the most prevalent, although you can also find enterprise-grade solutions with Oracle Database and/or PostgresSQL functionality. NoSQL databases (particularly MongoDB) are increasingly popular in the cloud, but at this stage you'll find some providers relying on partners to deliver the goods.
As for app dev services, partners often play a role, but take into account such providers as Google, Microsoft, Joyent, and others who began with PaaS and only recently ventured into IaaS. If their languages and development environments are on your wish list, your choice of IaaS provider may be an easy one. Note, however, that IaaS providers appear to be adding support for new app dev flavors and services all the time.
Be aware that some IaaS providers define PaaS as functionality to onboard and manage applications. We feel that's nonstandard and misleading; PaaS is really about providing an application development, testing, and deployment environment in the cloud. There's no shortage of those platforms of every possible variety, whether or not they're integrated into your IaaS provider of choice.
The IaaS explosion
Do any of the new providers have a shot at unseating Amazon? Not in the short term. The collection of products and services offered by Amazon Web Services would fill a small book, from a broad range of EC2 instance types to NoSQL databases to Hadoop/MapReduce services to virtual private cloud capability and a vast software marketplace.
And the leader is not standing still. In March 2012, Amazon struck a preemptive blow by dropping prices on both its EC2 service and its hourly rates for long-term contract customers. Prices for Reserved Instances, which involve a one-year contract, were sliced by up to a third. Even bigger volume discounts are available, but most of the cuts are intended to entice entry-level customers who could be lured by competitors. As before, you can take advantage of a yearlong free trial.
Still, many feel the luster of Google's highly touted infrastructure could lure customers who've held off venturing into the public cloud. And the hybrid approaches of Azure, HP, OpenStack, Rackspace, and others could prove successful as more enterprises adopt private cloud technology -- and the ability to "burst" from private to public IaaS infrastructure becomes a reality. Terremark is taking this hybrid approach, too, using one of the most advanced private clouds currently available: VMware's integrated suite of virtualization and cloud products. Terremark, like IBM, seems to prefer a phone call rather than self-provisioning when beginning IaaS relationships with enterprise customers.
Is the IaaS boom a fad or the beginning of an era where businesses decide they want someone else to maintain their infrastructure? That's a trick question because customers often discover, to their dismay, that they may have been be able to lay off a few admins who maintained in-house systems -- only to discover they need to hire other admins who specialize in an IaaS provider's feature set.
Over the long term, the mainstream drift may be toward SaaS, where everything underneath the application is truly handled by the provider. But at this particular moment, IaaS couldn't be hotter.
This story, "How to choose an IaaS provider," was originally published at InfoWorld.com. Follow the latest developments in cloud computing at InfoWorld.com. For the latest developments in business technology news, follow InfoWorld.com on Twitter.