The world of open-source cloud management platforms grew troubled last week as Citrix pulled its CloudStack away from OpenStack over questions of software maturity and the Amazon API.
Nineteen companies threw their weight behind the OpenStack cloud management platform (CMP) late last week. Those signaling their intention to become Platinum members of the nascent OpenStack Foundation, at $500,000 per year, were AT&T, Canonical, HP, IBM, Nebula, Rackspace, Red Hat, and SUSE. Among those signing up for Gold membership status ($50,000 to $200,000 per year) were Cisco, Dell, Yahoo, and NetApp.
IBM's support of OpenStack was news, though it had been rumored for a few weeks. (Big Blue has been contributing code to OpenStack.) Angel Diaz, VP of Cloud Standards at IBM, claimed that the architecture of IBM's own cloud services delivery platform will mesh well with OpenStack, according to CRN.com. This stance accords with our speculation earlier in the week at the announcement of IBM's PureSystems initiative.
OpenStack is the open-source cloud management platform with the all of the momentum. It began in 2008 as a project within NASA, and in 2010 merged with a similar effort that had been incubating within Rackspace. Of the 155 organizations on record as supporting OpenStack, 55 contributed code to the latest release.
Until very recently, Citrix was a vocal supporter of OpenStack, though it hasn't contributed much code recently. Its plan of record had been to integrate OpenStack with its own CloudStack, technology it acquired last year with the purchase of Cloud.com. CloudStack was an open-source project run on an open-core, closed-extensions model. Now Citrix has made it fully open-source by donating the lot to the Apache Software Foundation under an Apache 2.0 license. (Citrix withheld some pieces that had been licensed on terms incompatible with the Apache license.)
Tellingly, no vendors stood up with Citrix at its announcement to pledge support for CloudStack. To date, committers to the CloudStack open-source project have been almost solely Cloud.com or Citrix.
CloudStack is generally believed to be more mature, stable, robust, and production-ready than OpenStack. OpenStack has been characterized as "challenging" to work on even by its supporters, according to Gartner's Lydia Leong, who called OpenStack "a highly immature platform" that is "unstable and buggy and still far from feature-complete." (These comments came before the current "Essex" release went live; Essex focuses on stability and being production-ready, according to ReadWriteWeb's Joe Brockmeier.)
From the standpoint of the maturity of the institution controlling the code, CloudStack is far ahead: the Apache Software Foundation is long-established and has a solid track record of shepherding successful open-source projects (examples: Hadoop, Cassandra, Apache HTTP Server). The OpenStack Foundation has just barely been born; it won't be ready to take over full management of the code and the community until later this year.
Besides code maturity and stability, Citrix's big beef with OpenStack was the latter's wavering support for Amazon's API. OpenStack presents its own API, but also offers Amazon API compatibility as an option on the side. OpenStack's community has been "waffling about whether or not they want to continue to support" such compatibility, according to Gartner's Leong. Citrix clearly believes that Amazon compatibility is essential in a production cloud, owing to Amazon's dominance of the public-cloud space. OpenStack prefers to envision a world in which customers are free to move their data and code among a number of OpenStack-based clouds.
Some OpenStack supporters have issued overblown warnings about a "zombie apocalypse" if Amazon pulls support for the companies using its API, or worse, turns on them with patent lawsuits. These eventualities seem highly unlikely. Amazon inked a deal with another open-source CMP supplier, Eucalyptus, to help it perfect its Amazon-compatible API; some observers believe a similar deal could happen for Citrix's CloudStack.
As companies lay their cloud plans, they will do well to watch how this philosophical difference of opinion plays out. In the very near term, Amazon compatibility may be important, and agility could well be served by choosing a partner with the most mature platform on which to develop. In the longer term, greater agility will come from not being locked into any one vendor's cloud.