Over the last five years, since the release of the first open-source version of OpenNebula in March 2008, we have been involved in many presentations, discussions and meetings where people wanted to know how OpenNebula compares with the rest of open-source Cloud Management Platforms (CMPs), mostly with Eucalyptus and OpenStack. The most common understanding is that all CMPs are competing in the same market, trying to fill the same gap. Consequently, people jump to the wrong conclusion that after years of a fierce competition, there will only be one winner, a single open-source CMP in the market. However, as discussed by Joe Brockmeier in his post “It’s Not Highlander, There Can Be More Than One Open Source Cloud”, there is room in the market for several open-source CMPs that, addressing different cloud niches, will fit together into a broad open cloud ecosystem.
Two Different Cloud Models
Although there are as many ways to understand cloud computing as there are organizations planning to build a cloud, they mostly fall between two extreme cloud models:
The following table describes the main characteristics of both types of clouds. This is not an exhaustive list, I’m just putting it here to illustrate some of the differences between both philosophies.
|Datacenter Virtualization||Infrastructure Provision|
|Applications||Multi-tiered applications defined in a traditional, “enterprise” way||“Re-architected” applications to fit into the cloud paradigm|
|Interfaces||Feature-rich API and administration portal||Simple cloud APIs and self-service portal|
|Management Capabilities||Complete life-cycle management of virtual and physical resources||Simplified life-cycle management of virtual resources with abstraction of underlying infrastructure|
|Cloud Deployment||Mostly private||Mostly public|
|Internal Design||Bottom-up design dictated by the management of datacenter complexity||Top-down design dictated by the efficient implementation of cloud interfaces|
|Enterprise Capabilities||High availability, fault tolerance, replication, scheduling… provided by the cloud management platform||Most of them built into the application, as in “design for failure”|
|Datacenter Integration||Easy to adapt to fit into any existing infrastructure environment to leverage IT investments||Built on new, homogeneous commodity infrastructure|
Two Different Flavors of Cloud Management Platforms
Existing open-source CMPs can be placed somewhere in between both models. We have created a chart, the CMP Quadrant, aiming to aid corporations to better understand the present and future landscape of the cloud market. One of the dimensions is the “Cloud Model” and the second one represents “Flexibility” in terms of the capabilities of the product to adapt to datacenter services and to be customized to provide a differentiated cloud service. This dimension captures the grade of adaptability of the product, and goes from low to high. Finally, we have placed in the chart the main open-source players in the cloud ecosystem: Eucalyptus, CloudStack, OpenStack and OpenNebula… or at least those tools that are commonly compared to OpenNebula by our users and customers.
Comparing vCloud to AWS or comparing vCloud to OpenStack is like comparing apples to oranges as it has been clearly expressed by Massimo Re Ferrè and Boris Renski respectively. Both are fruits but with very different flavor. That being said, it is clear that since all the tools enable infrastructure cloud computing, there is always some overlap in the features that they provide. This overlap tends to be larger for those tools that are closer on the “Cloud Model” axis.
Looking to the Future
In OpenNebula, we do not think that one cloud model will dominate over the other. They may converge at the very long term, but not before 10 years. Consequently, and because a single CMP can not be all things to all people, we will see an open-source cloud space with several offerings focused on different environments and/or industries. This will be the natural evolution, the same happened in other markets. The four open-source CMPs will coexist and, in some cases, work together in a broad open cloud ecosystem.
We are sure that in the short term we will see some of the open-source CMPs working together, while at the same time finding ways to differentiate themselves in their own cloud markets.