Guide to app portability and interoperability
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As competition increases among cloud providers, enterprises have bandied about cloud portability concerns.
The ability to move applications from one cloud service provider to another is particularly important to IT pros that need the freedom to bargain shop. Companies that launch in the cloud without having an exact business model or an idea of how successful their product will be a few months down the road are often caught off guard with quickly escalating monthly charges for virtual machines (VMs).
It was getting quite expensive because [Rackspace] had bundled resources and we had to deploy resources we didn't really need.
For one U.S.-based financial insurance company looking to move workloads to Amazon Virtual Private Cloud (VPC), the ability to start with Amazon Web Services (AWS) and later move to another cloud, like Windows Azure, is a main consideration.
"We're looking at the long term," said an infrastructure architect who requested anonymity during the recent AWS Summit in San Francisco. "Amazon is flexible enough, but the ability to move certain apps to Azure will fall on us. So that is something we're hesitant about."
Similarly, small companies that select one cloud provider at inception may find the services no longer fit their needs.
Just how difficult is it for companies already established in the cloud to move VMs to another provider? It depends on their size.
Cloud portability considerations
Grespr, a Nepal-based Web-crawling service for enterprises that is built solely in the cloud, found itself in need of a switch.
"We didn't want to spend a lot of time in the beginning looking for a cloud provider," said Amit Chaudhary, the company's co-founder.
He was familiar with Rackspace Inc. through a former employer and went with that cloud provider, knowing it offers good service and is easy to use. But once Grespr began to grow, so did the cost of using Rackspace.
"It was getting quite expensive because they had bundled resources and we had to deploy resources we didn't really need," Chaudhary said.
For example, when Grespr's developers needed to deploy a small Web server, it had to purchase more than necessary.
"We didn't really require a 32-bit server, but we still had to pay for that," he said.
Chaudhary shopped around online for a new cloud and found CloudSigma, an Infrastructure as a Service (IaaS) provider based in Zurich. CloudSigma gives customers the ability to choose exactly what they need from their VMs and allows them to customize according to factors like CPU performance, hard-disk size and RAM size.
"We need a lot of disk space, and when you compared it to [CloudSigma], Rackspace's SSDs [solid-state drives] are [more expensive than] what CloudSigma offers," he added. CloudSigma prices start at $0.14 per GB per month for RAID-protected SSD storage, with volume discounts available. Rackspace SSD volumes run $0.50 per GB per month.
Grespr, which mainly crawls websites based in the U.S., had its concerns, however.
"Our first apprehension was whether or not connectivity would be as good as what Rackspace offers in the U.S.," Chaudhauy said.
There was also a learning curve on how to deploy servers on CloudSigma, because its approach is different than other providers, he said. But being a small company, Chaudhauy didn't find the move too difficult.
"We migrated all our servers one by one and then did testing for a couple of weeks," he said.
Rackspace also didn't offer the same level of flexibility, he said.
"We don't have to think about doing a new VM [in CloudSigma]," Chaudhary said. "If you want to do a new VM in Rackspace, you had to take at least a minimum one, but here you can choose what you need and the associated cost is very low."
Application design eases cloud portability
For cloud portability to work, applications must be compatible with the platforms of both cloud providers, said Tom Nolle, president of CIMI Corporation, a consulting company. And this includes any hardware, software or services like databases that the applications use.
In addition, management and integration tools need to match both cloud stacks, or companies looking to move to a new cloud provider have to invest time and money to re-architect applications.
Thinking about the project's future and how you build your applications two or three years down the line could pay off.
"… Think about where you're going and think about whether you want to tune your environment to the cloud limitations or tune the cloud to maximize your application requirements," said Dan Lucky, vice president of cloud solutions at Micro Strategies Inc., a cloud integrator and IBM partner, in a previous Q&A.
For Music Mastermind, an online app with 300,000 users that launched in AWS in 2011, moving off the cloud giant wasn't a simple task. The company's migration from AWS to IBM SoftLayer required the help of a skilled integrator and a nearly complete overhaul of its designs.
"[Music Mastermind's] original private cloud design is 100% different [from how] it is now," Lucky said. "If you design it wrong and have no flexibility, you're going to pay an awful price."
Michelle Boisvert is executive site editor for SearchCloudComputing, SearchWindowsServer and SearchDataCenter. Contact her at firstname.lastname@example.org.