The notion of hybrid cloud computing is gaining traction.
While the concept isn't all that new, vendors are constantly adding to the ways IT managers can effectively migrate and manage these
First, understand any infrastructure available from your cloud provider, particularly when it comes to using virtual private networks (VPNs), segmenting the cloud into a series of virtual LANs and setting up (and tearing down) virtual machine (VM) instances in the cloud.
As more servers start moving over to the cloud, you'll want easier and easier ways to migrate them. With some providers, a Web browser on their portal page and a few mouse clicks can clone your existing virtual server and have it up and running. Amazon has Auto Scaling and Elastic Load Balancer features to add or subtract computing resources, and Appistry has its CloudIQ servers that can help scale your cloud-based servers up or down.
"It all starts with design," said Bryan Doerr, the CTO of Savvis. "Make sure you understand the performance and security characteristics of the cloud so that you can achieve the levels you expect."
"Also," Doerr noted, "understand what kinds of support are possible in the cloud. If you are not monitoring the performance by your own staff, you may need your service provider to do that."
Next, consider your bandwidth and latency requirements carefully. "Make sure your existing network is ready for the migration to the cloud and is fast enough internally and with a fast Internet connection," said Dave Cutler, the general manager with Slalom Consulting, a national consultancy in Chicago. "You need to have a sufficient network pipe to support your users so they don't perceive any performance degradation."
You'll also want to have a secure method to access your servers and data. Most providers offer a VPN for this access. Amazon, for example, has its Virtual Private Cloud service, and Vyatta has an application that allows a network to be segmented virtually.
Other cloud providers only make use of secure HTTP browsers, remote desktop connections or SSH terminal sessions, which are much more limited. Having this segmentation increases your security posture and makes your cloud easier to manage as it grows.
It's also important to determine what level of granularity is offered and what's required for accessing cloud resources. With some providers, access is an all-or-nothing proposition. Look for more granularity and the option to limit what ordinary users can do, such as prevent them from stopping or starting a virtual server or making changes to your virtual infrastructure.
Finally, consider a staged approach for your cloud migration, which can be especially helpful to acclimate your staff to its way of life. This is what San Francisco-based Presidio Health did.
How Presidio Health made the hybrid cloud leap
"Presidio had to handle a 16 times increase in data volume in a year and replace some aging hardware," said CTO Thomas Gregory. "We didn't want a lot of capital expense, and we wanted an environment that was safe and could spread our risk around."
The health care software provider took a multi-stage process toward cloud computing by keeping its data inside its data center but migrating apps to the cloud. "We were able to increase our computing power by 70% without increasing our IT budget," Gregory said.
The next stage was to move its data over to the cloud.
"Having the first step of a hybrid cloud was more complex, but it gave us some experience with handling the cloud apps and understanding the security implications," Gregory noted. "It was a lot easier to leave our back-end servers in our cabinets while we migrated the front end. And anyway, most of the cloud environment deals with the front-end interfaces, so that gave us time to work on those."
The company uses a combination of Eclipse and Spring-based open source software, Appistry for handling their cloud services management and hosts everything at Sacramento-based StrataScale.
"We wanted a provider that was close enough to get to in an emergency but not located in the same earthquake fault zone as our offices," Gregory said.
What made this two-staged process successful was planning out the entire process in advance. "You need to take the time to analyze what you have," Gregory said, "and find a solution that will allow you to scale what you have and make the necessary adjustments along the way."
For more specific recommendations, take a look at other tool recommendations for managing private clouds. It's a helpful, and necessary, batch of hints for those considering a hybrid cloud computing move.
ABOUT THE AUTHOR:
David Strom is an expert on network and Internet technologies and has written and spoken on topics such as VOIP, convergence, email, network management, Internet applications, wireless and Web services for more than 20 years. He has had several editorial management positions for both print and online properties in the enthusiast, gaming, IT, network, channel and electronics industries.
This was first published in May 2011