More than one way to build a cloud (and there always will be)
Feel the fabrics
Cloud The open systems revolution of the late 1980s and early 1990s, which espoused interoperability between platforms, made the various Unix operating systems the world’s most popular server platforms.
If you consider Linux a kind of Unix, then you can argue that although Windows has spread into small and medium businesses, the Unix platform still dominates the enterprise server landscape.
The openness in Unix and Linux has helped these systems maintain their position in the market, even though Windows has an order of magnitude more software developers.
People do learn. When any new technology comes down the line, thanks to the healthy effects of the open-systems approach, there is soon a call for standards and interoperability through common APIs and open source code.
The open call is now being made for the brains behind computing clouds – what are often called cloud fabrics or cloud controllers.
These are the traffic cops controlling how hypervisors and virtual machines are fired up and shut down on the clusters of servers that are wired together as a giant pool of CPU capacity.
Cloud fabrics are the über operating system – and the high ground from which key software suppliers will try to dominate the virtualisation field. And that means, despite all the talk of cooperation and openness, vendors will be tempted to make their platforms better and maintain some incompatibilities.
We're in the money
VMware, the server virtualisation industry juggernaut, took an early lead with its ESX bare-metal hypervisor. Although VMware likes to pretend that many of the components in its vSphere stack of server virtualisation tools are add-ons to the hypervisor, most of the advanced functions, such as live migration, backup, failover and other virtual machine features, are coded in the hypervisor and accessed through its vCenter console.
The company's vCloud Director, on the other hand, is a cloud fabric. It wraps around multiple instances of ESX hypervisors and vCenter controllers and adds capacity management, metering and orchestration functions, as well as a self-service portal.
This last is key because it allows end-users to request computing, storage and networking resources from the IT department in a consistent manner, and enables the IT department to deliver it in a consistent manner.
It is a closed system just as much as Windows is
Importantly for VMware, vCloud Director manages only ESX virtual machines. It is a closed system just as much as Windows is.
There’s some big money to be made here. The first release of vCloud Director spans up to 25 vCenter consoles and up to 10,000 concurrent-running virtual machines. vCloud Director costs $150 (£90) per virtual machine under management when it is used with the vSphere stack.
The Request Manager portal costs another $100 (£60) per virtual machine and the Capacity IQ capacity planner costs an additional $75 (£45) per virtual machine. On a cloud with 10,000 virtual machines, The vSphere Enterprise Plus hypervisor and vCenter consoles would cost $3.8m( £2.3m) at list price, and the vCloud extensions would cost another $3.25m (£2m). This is not petty change: each piece – hypervisor and cloud fabric – individually rivals the cost of hefty two-socket servers underlying the cloud, which might cost somewhere around $3.5m (£2.1m) for the 450 machines making up that cloud.
Jaunty Red Hat
Unsurprisingly, the open-source community sees this kind of lock-in and those kind of prices, and declares it has a better idea.
Commercial Linux distributor Red Hat, which has done the best job of turning the open-source Linux and Java middleware stacks into a growing and profitable business, ate Qumranet a few years ago to gain control of the KVM (kernel-based virtual machine) hypervisor.
With the RHEL Enterprise Linux 6 operating system announced last autumn, the KVM hypervisor is ready for primetime and has been extended with its own cloud fabric, which Red Hat calls the Cloud Foundations stack.
Red Hat is putting forth its own KVM and related tools as all that is needed to create a cloud. But the company is also talking up its Deltacloud management APIs, and promising interoperability with private clouds based on VMware's ESX or Microsoft's Hyper-V, as well as public clouds created by Amazon, IBM and others.
Red Hat does not provide a price for its cloud stack, but presumably if you buy enough hypervisors and support contracts, it will be lower than what VMware is trying to charge.
Eucalyptus Systems, which created a mostly open-source cloud fabric that emulated Amazon’s EC2 cloud using a homegrown Xen hypervisor, looked like it might be the cloud fabrics leader to rival VMware. With Canonical embedding Eucalyptus in its own Ubuntu Enterprise Cloud, it certainly looked that way.
But then NASA and Rackspace Hosting decided to work together with a who's who list of IT vendors to make a cloud fabric that is completely open source. That software, called OpenStack, is evolving fast, has a lot of energy behind it, and aims to create a cloud that can span one million host servers and control up to 60 million virtual machines at once.
And if history is anything to go by, commercial support for OpenStack will be a lot cheaper than VMware's vCloud Director, once companies start offering support services for it the way Red Hat and Canonical do for Linux. In fact, it probably won't be long before both Red Hat and Canonical adopt OpenStack as their cloud controllers of choice.
Don't expect VMware or Microsoft to follow suit any time soon, though. ®