The OpenNebula Engine for Data Center Virtualization and Cloud Solutions

By Ignacio Martin Llorente

Virtualization has opened up avenues for new resource management
techniques within the data center. Probably, the most important
characteristic is its ability to dynamically shape a given hardware
infrastructure to support different services with varying workloads.
Therefore, effectively decoupling the management of the service (for
example a web server or a computing cluster) from the management of the
infrastructure (e.g. the resources allocated to each service or the
interconnection network).

A
key component in this scenario is the virtual machine manager. A VM
manager is responsible for the efficient management of the virtual
infrastructure as a whole, by providing basic functionality for the
deployment, control and monitoring of VMs on a distributed pool of
resources. Usually, these VM managers also offer high availability
capabilities and scheduling policies for VM placement and physical
resource selection. Taking advantage of the underlying virtualization
technologies and according to a set of predefined policies, the VM
manager is able to adapt the physical infrastructure to the services it
supports and their current load. This adaptation usually involves the
deployment of new VMs or the migration of running VMs to optimize their
placement.

The dsa-research group
at the Universidad Complutense de Madrid has released under the terms
of the Apache License, Version 2.0, the first stable version of the OpenNebula Virtual Infrastructure Engine.
OpenNebula enables the dynamic allocation of virtual machines on a pool
of physical resources, so extending the benefits of existing
virtualization platforms from a single physical resource to a pool of
resources, decoupling the server not only from the physical
infrastructure but also from the physical location. OpenNebula is a
component being enhanced within the context of the RESERVOIR European Project.

The new VM manger differentiates from existing VM managers in its
highly modular and open architecture designed to meet the requirements
of cluster administrators. OpenNebula 1.0 supports Xen and KVM
virtualization platforms to provide several features and capabilities
for VM dynamic management, such as centralized management, efficient
resource management, powerful API and CLI interfaces for monitoring and
controlling VMs and physical resources, fault tolerant design... Two of
the outstanding new features are its support for advance reservation
leases and on-demand access to remote cloud provider

Support for Advance Reservation Leases

Haizea
is an open source lease management architecture that OpenNebula can use
as a scheduling backend. Haizea uses leases as a fundamental resource
provisioning abstraction, and implements those leases as virtual
machines, taking into account the overhead of using virtual machines
(e.g., deploying a disk image for a VM) when scheduling leases. Using
OpenNebula with Haizea allows resource providers to lease their
resources, using potentially complex lease terms, instead of only
allowing users to request VMs that must start immediately.

Support to Access on-Demand to Amazon EC2 resources

Recently, virtualization has also brought about a new utility
computing model, called cloud computing, for the on-demand provision of
virtualized resources as a service. The Amazon Elastic Compute Cloudi
s probably the best example of this new paradigm for the elastic
capacity providing. Thanks to virtualization, the clouds can be used
efficiently to supplement local capacity with outsourced resources. The
joint use of these two technologies, VM managers and clouds, will
change arguably the structure and economics of current data centers.
OpenNebula provides support to access Amazon EC2 resources to
supplement local resources with cloud resources to satisfy peak or
fluctuating demands.

Scale-out of Computing Clusters with OpenNebula and Amazon EC2

As use case to illustrate the new capabilities provided by OpenNebula, the release includes documentation
about the application of this new paradigm (i.e. the combination of VM
managers and cloud computing) to a computing cluster, a typical data
center service. The use of a new virtualization layer between the
computing cluster and the physical infrastructure extends the classical
benefits of VMs to the computing cluster, so providing cluster
consolidation, cluster partitioning and support for heterogeneous
workloads. Moreover, the integration of the cloud in this layer allows
the cluster to grow on-demand with additional computational resources
to satisfy peak demands.

Ignacio Martín Llorente

Reprinted from blog.dsa-research.org

Cloud Caucusing

By Rich Wellner

Several months ago on this blog, I mused on what was meant by the term cloud computing.  At the time, it was even more difficult than it is today to get a solid definition of the concept.  Since then, many opinions have been bandied about providing plenty of fuel for the debate.  While I think the concept has solidified some, cloud computing remains a highly polysemous term where folks from different backgrounds have developed their own definitions based upon their particular worldviews.  These viewpoints come from vendors, specialists, researchers, as well as different user communities.

Although a unified definition for cloud computing has not emerged, the concept has gained a lot of traction. I believe that this is because each interested-group has found significant promise in what they call the cloud. Of course anything with this much possibility will certainly see some hype.  As I have said, before: the term invokes thoughts of transient beauty and power: even marketing folks can get excited with this one!  (Compare that to SaaS).

In any event, I thought that I would give you a quick idea of the types of discussions going on around cloud computing on the internet:

• Twenty Experts Define Cloud Computing;
• The Next Perfect IT Storm;
• Google Groups “Discussion on the-definition-of-a-cloud-of-computers”;
• Cloud Computing Promise & Reality (from which we learned, “There is a clear consensus that there is no real consensus on what cloud computing is.”  Bob Buderi, founder and CEO of Xconomy);
• Cloud Computing Hype versus Reality;
• Wiki Definition.
  

Compare these to one of the earliest usages of the term (search for cloud).  Clearly, these documents are far from a representative set of the discussions going on out there.  It just so happened that I selected a few from those I have read lately. There really is a lot going on out there.

Ultimately I expect to see many types of formalized clouds, each depending on their
operating environments and behaviors — just like I see when I look outside my
window. Once that happens, the big debates about how to interoperate between clouds of very different nature will begin. Transforming a concept into a widely accepted framework is never easy.  After all, why should I have to bend my perfect cloud so that it works with yours?

So what is the upside of all this banter? It turns out that the less often a word is used, the faster it evolves. Ironically, the hype may actually force this community into consensus.  As long as we keep this dialog going, we should expect a formalized cloud to come about in no time!!!

A Cloud by Any Other Name

By Rich Wellner

The cloud list on google has been buzzing lately about the term "Enterprise Cloud" and whether it had any significance.

I had to chuckle as history started to repeat itself again between the early days of the grid and the early days of the cloud.

In our book Pawel and I wrote a section titled "How the Market Understands Grids". We didn't try to dictate terms, we tried to document the language in place at that moment in time.

In interviewing users we gathered the following terms:

• Clusters -- Computers standing together, but accessible only to a small group of people
• Departmental grids -- Multiple clusters accessible on a common backplane, but owned by one department
• Enterprise grids -- Corporate resources available to all in the company (known today as a Enterprise Cloud)
• Partner grids -- A few companies working together on big problems and sharing resources to accomplish their goals.
• Open grids -- Many organizations making resources available to other members of that grid. A key distinction between an open grid and a partner grid is that an open grid doesn't typically have a key application or goal while a partner grid does.

We blanched a bit because to us grid computing meant only the last definition and we viewed those other ones as missing some key attributes that those of us who had been working in the grid field since its inception thought were really important.

We see the same thing happening today with the term cloud and particularly in the term Enterprise Cloud.

That said, is Enterprise Cloud really an oxymoron, as one person suggested?

First we have to get to definitions:

Here are the key characteristics from the cloud computing wiki:

• Capital expenditure minimized and thus low barrier to entry as infrastructure is owned by the provider and does not need to be purchased for one-time or infrequent intensive computing tasks. Services are typically being available to or specifically targeting retail consumers and small businesses.
  
• Device and location independence which enables users to access systems regardless of location or what device they are using (eg PC, mobile).
  
• Multitenancy enabling sharing of resources (and costs) among a large pool of users, allowing for:
  
  • Centralization of infrastructure in areas with lower costs (eg real estate, electricity)
    
  • Peak-load capacity increases (users need not engineer for highest possible load levels)
    
  • Utilization and efficiency improvements for systems that are often only 10-20% utilised.
    
• Performance is monitored and consistent but can be affected by insufficient bandwidth or high network load.
  
• Reliability by way of multiple redundant sites, which makes it suitable for business continuity and disaster recovery, however IT and business managers are able to do little when an outage hits them.
  
• Scalability which meets changing user demands quickly, without having to engineer for peak loads. Massive scalability and large user bases are common but not an absolute requirement.
  
• Security which typically improves due to centralization of data, increased security-focused resources, etc. but which raises concerns about loss of control over certain sensitive data. Accesses are typically logged but accessing the audit logs themselves can be difficult or impossible.
  
• Sustainability through improved resource utilisation, more efficient systems and carbon neutrality.
  

None of those seem to exclude the term Enterprise Cloud.

Here's the list of attributes I compiled from the cloud google group and others IRL:

• Multiple vendors accessible through open standards and not centrally
  administered
  
• Non-trivial QOS (see the gmail debate thread)
  
• On demand provisioning
  
• Virtualization
  
• The ability for one company to use anothers resources (e.g. bobco
  using ec2)
  
• Discoverability across multiple administrative domains (e.g.
  brokering to multiple cloud vendors)
  
• Data storage
  
• Per usage billing
  
• Resource metering and basic analytics
  
• Access to the data could me bandwidth/latency limitations, security,
  
• Compliance – Architecture/implementation, Audit, verification
  
• Policy based access – to data, applications and visibility
  
• Security not only for data but also for applications
  

Now here we start to see some things that aren't applicable to enterprise clouds (i.e. 1, 5, 6). But the bulk of the list still works. And it's worth noting that EC2 fails on four of those things (i.e. 1, 11, 12, 13), but people don't hesitate to allow them the use of the term cloud.

In previous technology revolutions I learned the lesson (slowly) to not care so much what things are called as much as what they do (which was why, in my early writings on this group I was trying to point out to people (mostly unsuccessfully) that there are lessons to be learned from grid computing). But claiming there is a canonical definition of cloud and that enterprise cloud is a nonsense term doesn't seem accurate on the face of things. Enterprise Cloud does, however capture the essence of what many large corporate IT groups are doing/considering. Rather than telling them they shouldn't be calling it cloud/grid/enterprise cloud/managed services/SaaS/whatever, I'm taking the approach of helping them meet their business needs, with technology wearing a variety of banners, and letting them call it whatever they like.