Java in the cloud: Google, Aptana, and Stax
Google App Engine, Aptana Cloud, and Stax for EC2 make it easy to spin up and scale a simple Java Servlet Container, but are still a far cry from the full Java EEFollow @infoworld
Both Aptana and Stax offer more standard solutions that can easily be duplicated because they're just Tomcat and a database under the hood. There's much less lock-in with their tools because you can pretty much take your WAR file to any other server farm. You'll have to handle all of the deployment issues yourself, but it's feasible.
Aptana might be more useful to someone writing applications that will run on one server. It's a great tool for prototyping new systems and getting them on the Internet quickly.
Stax offers more room to scale because it deploys the application to multiple servers and load balancers with just one click. I think it offers a nice mixture of the scalability of Google with the openness of Aptana.
It's worth noting that some applications aren't well supported by any of these choices. These three are not great solutions for jobs that require bursts of heavy computation like, for instance, geologists prospecting for oil with big numerical processing simulations that churn through terabytes of data. Even though these applications are often highly parallel, they aren't great matches for any of these services. Stax is probably the best choice because it lets you click on a button to launch your application on five computers, but it's still intended for Web servers and five is only five. The ideal solution for these heavy computational jobs would let you start up thousands of machines for just an hour.
Java cloud futures
These clouds may grow to take on roles like this in the future, but for now I think they're still working through many of the accounting challenges of starting up and shutting down machines so quickly. These companies can't be certain of the best ways to plan ahead or to price their services. Some commerce sites say that people like to shop online during their lunch break. Video sites must be pounded during prime time. Balancing these loads must be a real challenge for these back ends.
The pricing is a bit hard to compare. Stax is still in beta and it hasn't announced prices. Aptana has just four settings that tie everything together. The amount of disk space you get is tied to the amount of memory you allocate. One hour of CPU time can vary between $0.027 and $0.359. You pay this whether your machine is doing something or not.
Google, on the other hand, breaks up the bill and charges for bandwidth, stored data, e-mail, and CPU time. The price of $0.10 for the CPU seems more expensive because the cost is computed per thread. I was easily able to handle four or five requests at the same time with the cheapest setting on Aptana Cloud. But this doesn't mean that Aptana's cloud is wildly cheaper, because Google's cloud doesn't bill you if there are no requests coming in. It's very difficult to compare these offerings, and I'm sure that different applications will run up very different bills on each service.