Cloud versus cloud: A guided tour of Amazon, Google, AppNexus, and GoGrid

Cloud computing offerings differ in depth, breadth, style, and fine print; beneath the heady metaphor lurk familiar pitfalls, complex pricing, and many questions

 

AppNexus
If you like the idea of the cloud but aren't sure if you want to leave behind the old trustworthy world of Unix, cron jobs, and other tools, then AppNexus is a service that aims to be a bit more transparent. The company has taken a big, industrial-sized server farm with the best load-sharing tools and storage boxes and found a way to let you buy it in small portions. AppNexus provides a number of command-line abstractions that let you turn servers on and off, but they also let you drill down into the file system.

The main functions of the AppNexus cloud are similar to Amazon's EC2. You log in through a command line and boot up images of Linux distributions. AppNexus says it can rebuild images from other sources like Amazon's EC2 by replacing the kernel with a version that's more aware that it is running in a virtual environment. Then it just takes a few key clicks on a command line to set up a load balancer.

One open question in the world of cloud computing is where the abstraction occurs; that is, where do the walls between the machines become blurred and it all starts to look a bit cloudy? Amazon's SimpleDB hides the storage behind a software wall and gives you access to it through some Web service call. AppNexus is working at a lower level by building in a cluster of Isilon IQ X-Series storage clusters into its cloud.

This gives you the option of simply mounting the storage and sharing the data across your cluster of servers -- if you consider that simple. Instead of working with abstract keys, you use real file names as the keys. The cluster handles the rest of the work.

A better solution is to use what AppNexus calls its CDN, or Content Delivery Network. The storage cluster has its own set of HTTP servers built in, and you can automatically begin serving static data from your files. Just write the files to the /cdn directory and they become available. AppNexus will distribute this storage cloud to multiple datacenters, making it simpler to serve up the static data from the closest location. [ See the QuickTime video. ]

The Bottom Line

Amazon Elastic Compute Cloud Amazon, amazon.com/ec2

Preview

Cost: 10 cents per hour for a "small instance" (1.7GB of memory, 160GB of instance storage), 15 cents per gigabyte of data storage per month, 10 to 17 cents per gigabyte of data transferred Platforms: Linux-based systems Bottom Line: Amazon EC2 offers a great collection of tools and experimental offerings that is rapidly expanding. Already offering the broadest set of cloud services by far, Amazon supports a wide range of application platforms including JBoss, and active development shows the cloud changing day by day. Cons include endless cutting and pasting for the command-line interface, and the shared storage (S3) is relatively expensive for low-grade data such as log files.

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The Bottom Line

Google App Engine Google, google.com/appengine/

Preview

Cost: About 5 million free page views. After that, 10 to 12 cents per hour of a CPU core, 15 to 18 cents per gigabyte of storage per month, and 9 to 13 cents per gigabyte of data transferred. Platforms: Any Python 2.5 Web application that operates in a sandbox that excludes actions such as writing to the file system. Bottom Line: App Engine makes life easy for programmers who code simple database front ends in Python, though the API is deliberately limited. There are no background threads, files, or other crutches. It's all database, all the time, but only a simplified database at that. The pricing model -- based on squirrelly metrics such as CPU megacycles -- may make costs difficult to anticipate. An application dashboard offers clean views of performance.

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The Bottom Line

GoGrid GoGrid, gogrid.com

Preview

Cost: 12 cents per hour of a CPU core. Load balancing, DNS, 500GB of storage, and incoming data transfers are free. Outbound data transfers cost 25 cents per gigabyte Platforms: CentOS and Red Hat Enterprise Linux with Apache, PHP, MySQL, or Facebook; Windows Server 2003 with IIS, ASP.Net, SQL Server 2005 Bottom Line: GoGrid offers the widest range of machine images, including Windows systems. A clean, AJAX-based control panel makes it simple to get a sophisticated network up quickly and efficiently, and saves you the trouble of cutting and pasting IP addresses and other details. GoGrid doesn't offer many cloudlike features for database storage; you have to mirror the databases yourself. The company is still working on a way to freeze a machine instance so that you don't have to pay for it when it's not running.

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The Bottom Line

AppNexus AppNexus, appnexus.com

Preview

Cost: 22 cents per hour for a 2.83GHz server. High throughput NAS costs 50 cents per gigabyte per month, while archival storage costs significantly lower. Platforms: Linux-based systems Bottom Line: AppNexus is a way to share the cost of owning top-of-the-line enterprise tools. It makes load balancers and file storage systems available on a fractional basis, and it provides a content delivery network that spreads your static files throughout the Web. Cloudlike features are implemented with old-school metaphors like "shared file systems," which may be a good thing if you like the old transparency. The command-line interface is really made for Unix lovers.

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