Next to security, it's probably the second biggest worry that IT executive have over cloud architectures.
I'm talking about interoperability. The last thing anyone wants to do is transfer reliance from a wholly owned and operated data center to a cloud platform controlled by someone else. And it's not just a drawback of the public cloud. Rolling out an internal cloud based on a single provider's platform can lock you in just as badly.
There is a movement afoot to foster open, or at least interoperable, cloud standards, but it's hard to tell whether they will gain sufficient industry support to be truly effective. A standard is only as good as its acceptance allows it to be, and if multiple competing standards arise, then we're no better off than if there were no standards at all.
The latest group to take up the cause is Xen.org, overseers of the Xen hypervisor that fuels the Citrix/Microsoft virtualization/cloud platform. The group has come up with the Xen Cloud Platform (XCP) which promises to " accelerate the use of cloud infrastructure for enterprise customers by providing open source virtual infrastructure technology that makes it easy for service providers to deliver secure, customizable, multi-tenant cloud services that work seamlessly with the virtualized application workloads customers are already running in their internal datacenters and private clouds, without locking them into any particular vendor."
It certainly is a mouthful, but what the group essentially is saying is that it can leverage the open source nature of the Xen hypervisor, add in current standards like the Open Virtualization Format and a dose of federated computing technology, and come out with a set of virtual appliances and switching technology that can get hypervisor-independent cloud architectures up and running in a heartbeat. The idea is to provide for smooth translation of applications and data between internal and external clouds no matter whose hardware or software is in play.
It's a tall order, but the group does have some key backers, including Dell, AMD, Fujitsu and Juniper. It also goes to the heart of what many critics say is the chief flaw of the VMware platform -- that once you deploy its virtualization software it's very difficult, if not impossible, to work across platforms. When this was just an internal virtualization issue, the problem was muted. But now that the cloud is involved, VMware users could find themselves limited only to outside providers who can offer vSphere.
But even here, relief may be on the way from a third party. A start-up called Eucalyptus Software announced this week a new software package that brings open source interoperability to both the vSphere and ESX platforms. The company says it can match VMware to both Xen and KVM systems to produce a unified application environment for both internal and external cloud structures. The company specializes in open source interfaces that allow internal resources to coordinate with Amazon's EC2 cloud.
Still another offering comes from Red Hat, which has devised a "cloud broker" that allows applications to traverse multiple clouds. The Deltacloud system provides a set of drivers that map APIs to various cloud platforms, while an associated Web portal will provide the means to migrate multiple instances from one cloud to another. The system supports Red Hat Enterprise Virtualization and VMware ESX, and the company is in talks to bring Rackspace on board as well.
Does this mean we are on the verge of a fully interoperable cloud? Perhaps, but we're not there yet. Those of us who have grown accustomed to the Internet take it for granted that everything should work smoothly over a public network, but that isn't always so.
There are some powerful vested interests in play that would like nothing better than to have the whole pie to themselves. It's the job of open source supporters to convince them that they'll eat better by taking just a piece of a much larger pie.