In its approach to networking, short term storage, and services orientation, CloudStack is less like Amazon than OpenStack. In the area of cloud APIs, another open source company, Eucalyptus Systems possesses that as its specialty. Even Amazon agrees. When it wanted a partner in building private clouds compatible with EC2, it recently chose Eucalyptus.
CloudStack has to substitute a translator between CloudStack APIs and Amazon's APIs, called CloudBridge, changing EC2 API calls to CloudStack-native API calls. Eucalyptus' storage service API is so close to Amazon's that it can be safely substituted for AWS.'
For whatever reason, Citrix felt compelled to overstate its similarity to Amazon as it sought support for CloudStack as open source code. Under review, it doesn't stand up to the claim that it is "the only cloud platform on the market ... designed from the ground up with a true Amazon-style architecture."
"It's not even close," concluded Bias in offering a welcome antidote to Citrix's bias.
The Citrix statements play best only if they are taken in the context of its perennial competition with VMware. The latter's cloud products can probably be proven to be less Amazon-compatible than CloudStack, since it comes from a completely different technology base and set of objectives. But Citrix's competition with VMware is not a sufficient basis for establishing the best open source code project to support private clouds.
On the contrary, by one of the key metrics used by open source developers themselves--the commitment of the project to accomplish something new, something not yet fully in the open source arena, such as an innovative cloud computing stack--is a key measure of whether developers will support the project or not.
Another way of asking the same question is how many companies, and how diverse a group of companies, are supporting the project by contributing code? On that measure, OpenStack wins hands down. In Citrix's submission to the Apache Foundation, it was not able to list an extensive set of reviewers and contributors who were outside of Citrix, knowledgeable observers say.
CloudStack may yet emerge as a sustainable, long-term project, but one simply with a narrower base of support. Nothing wrong with that. Choice is good among open source projects, as well as commercial products. OpenStack now has IBM, Red Hat, Cisco Systems, HP, and 162 other companies behind it, support that appears to be diverse, coming from companies that are vastly different in size and hosting many individual contributors.
The OpenStack developers are consciously seeking some compatibilities with Amazon. At the same time they reserve the right to innovate in cloud computing as the members of the project see fit, rather than simply following Amazon's lead. That makes OpenStack a potentially good basis for building private enterprise clouds with a future measure of compatibility with Amazon, while not foreclosing the option of being more enterprise oriented than Amazon in certain areas.
Find out how to move beyond server virtualization to build a more flexible, efficient data center in the new Private Cloud Blueprint issue of Network Computing. (Free registration required.)