The Road To Open Federated Clouds: Xen, VMware And More

VMworld 2009 is over and the battle lines are already drawn between
Citrix Xen, Vmware and Redhat. Xen is the leader in the public cloud
service provider side and VMware holds near monopoly hold on the
enterprise infrastructure side. Before we see full scale cloud adoption
on the enterprise side, it is important that these technologies
interoperate with one another.

This week saw major
announcements from all three virtualization players that could
eventually lead to an open federated cloud ecosystem. But it is just a
start and these efforts should go well beyond the soundbites of the
occasion. It is a long road ahead but it is important that the process
is kickstarted sooner than later. Let us recap the events that unfolded
this week and try to understand it from the framework of open federated
cloud ecosystem.

Anticipating an announcement by VMware,
Xen.org, the competing virtualization hypervisor backed by Citrix
systems, announced their Xen Cloud Platform (XCP), an open source cloud
computing platform built on top of Xen hypervisor. The Xen Cloud
Platform will 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. The goal of XCP is to

• create a
  cloud computing platform with storage, servers and networks
  virtualized. The virtualized storage and servers are architected to be
  widely separated without disrupting application performance. The rich
  virtual networking capabilities adds sophisticated network service
  offerings, including per-tenant network management, intrusion
  detection, firewalling, routing, and load balancing
• run
  across many different virtualization platforms including Microsoft and
  VMware. Using different standards such as Distributed Management Task
  Force (DMTF) Open Virtualization Format (OVF), virtual appliances will
  be packaged in a hypervisor-independent format for easy transport
  between internal and external clouds with no proprietary vendor lock-in
• port
  applications running on enterprise datacenters (most of which is based
  on VMware’s technology) to Xen based cloud without any modifications
• simplify
  the process of moving workloads across many different clouds will make
  sure that the cloud ecosystem is federated. The fact that XCP is open
  source supporting open protocols and formats will ensure that the cloud
  ecosystem is open and federated

As expected, VMware came up
with their own announcement at VMworld. Their announcement was more
about talking than the walking. VMware announced the release of vCloud Express, directed towards the service providers to deliver Amazon EC2 like on-demand pay as you go services, and vCloud API, touting application mobility and cloud interoperability.

vCloud
Express is a set of services built on top of vSphere and delivered to
customers by the VMware service provider partners, which at this point
of time includes Terremark, Hosting.com, Logica, Bluelock and Melbourne
IT. Starting with an external vCloud environment, developers can deploy
it on secure, reliable enterprise clouds inside their datacenters. Even
though it is touted as an alternative to Amazon cloud, the very
economics will dictate otherwise. I see this as a threat to providers
like Skytap whose main differentiating element is their ability to move
enterprise workloads seamlessly into their cloud labs. Even though you
could hear the terms like interoperability and portability thrown along
with vCloud initiative, it is all about playing within the VMware
technological domain. There is enough merit to the noises made by pundits
about vendor lock-in. In short, according to VMware, users could enjoy
all the freedom as long as they do it on top of their own technologies.
No wonder people like Richard Stallman call Cloud Computing as a trap for vendor lock-in.

VMware
also announced the vCloud APIs which will help in deploying and
managing applications in different cloud environments through a RESTful
interface. The vCloud API enables the upload, download, instantiation,
deployment and operation of vApps (application appliances in OVF
format), networks and Virtual Datacenters (virtualized resources of
compute power, storage and network). This API will make it very easy to
move workloads from one cloud environment to another. In a way, this
helps in the development of a federated cloud ecosystem. The version of
API announced during VMworld is 0.8 (Technology Preview) and it is
openly available (note: it is not open source) for consumption. vCloud
API has also been submitted to the Distributed Management Task Force
(DMTF), a standards body working to develop standards that enable
interoperable IT management.

Not to be outdone by the news
coming out of the two major virtualization vendors, Redhat, the open
source giant who is propping up KVM over Xen after Microsoft friendly
Citrix bought them. Actually, there are two announcement from the
Redhat front. The first one is the integration of KVM at the kernel
level in the recently released RHEL 5.4 OS. They are pushing KVM really
hard. When their long support cycle for previous versions runs out in a
few years, we can expect them to dump Xen completely. Redhat’s
marketshare in Hypervisor market is very negligible but this is good in
the sense that there will be more choices and a wide array of choices
is a good thing for users.

The second announcement is the release of Deltacloud
which provides a portal for managing applications on many different
code with many different APIs. They offer a framework that makes it
easy for cloud providers to add their cloud to the Deltacloud common
API. It is a REST based API with support for Amazon EC2 and RHEV-M.
Pretty soon, they will be supporting VMware ESX and Rackspace. The best
part of this API is the backwards compatibility across versions,
providing long-term stability for scripts, tools and applications. The
Deltacloud Portal is the UI to manage the varying set of Cloud APIs.
Deltacloud is not only based on Open Standards but it is open source
too.

Let me do a short recap of the above

• VMware
  touts openness about their cloud APIs but we are yet to their API. Even
  though they have approached the standards body, it doesn’t mean
  anything till their API is widely tapped by the providers of other
  virtualization technologies
• Xen promises openness and open source but we have to wait fo some time to see them in action
• Redhat
  is the only one that touts openness and, also, open source. More
  importantly, they are the only ones who are offering the developers an
  interface to work with

With all the hoopla about standards, openness and open source, it is important to note the following

• Openness
  or open source doesn’t imply standards. The main keyword here is
  adoption. When it comes to the issue of adoption, VMware is going strong on the enterprise side and Xen on the public cloud side.
• Vendor
  lock-in implies the absence of freedom and any talk about portability
  with the lock-in mechanism activated is just meaningless. Any attempts
  by VMware to stop interoperability by means of restriction will backfire

It remains to be seen how much VMware is really committed to create an open interoperable federated system of clouds. Whatever
be the outcome of this game, one thing is clear. The future is an
ecosystem of open and federated clouds. The action by these three
virtualization vendors will go a long way in promoting such a future.