I wrote part 1 of this post last October, highlighting a Microsoft white paper that convincingly established the economic case for multi-tenant, public clouds over single-enterprise, private infrastructures. Part 2 would wait, I wrote then, for "the other shoe still waiting to drop ... a complete rebuttal of all the arguments over security, reliability and control that are made to justify private cloud initiatives. The dreadful fragility and brittleness of the private cloud model has yet to be fully exposed."
The other shoe dropped last month, and from an unexpected direction. Rather than an analyst survey or research finding, it came in a firestorm of tweets and two blog posts by a pair of respected enterprise IT folk. One of them is Adrian Cockcroft, CIO of Cloud Architect for Netflix, a passionate adopter of public cloud infrastructure. The other is Christian Reilly, who engineers global systems at a large multinational and had been a passionate advocate of private cloud on his personal blog and Twitter stream until what proved to be a revelatory visit to Netflix HQ:
"The subsequent resignation of my self imposed title of President of The Private Cloud was really nothing more than a frustrated exhalation of four years of hard work (yes, it took us that long to build our private cloud)."
Taken together, the coalface testimony of these two enterprise cloud pioneers provides the evidence I'd been waiting for to declare private cloud comprehensively discredited — not only economically but now also strategically. There will still be plenty of private cloud about, but no one will be boasting about it any more.
As both these individuals make clear, the case for private cloud is based on organizational politics, not technology. The pace of migration to the public cloud is dictated solely by the art of the humanly possible. In Cockcroft's words, "There is no technical reason for private cloud to exist." Or as Reilly put it, "it can bring efficiencies and value in areas where you can absolutely NOT get the stakeholder alignment and buy in that you need to deal with the $, FUD and internal politics that are barriers to public cloud."
Cockcroft's post systematically demolishes the arguments for public cloud:
- Too risky? "The bigger risk for Netflix was that we wouldn't scale and have the agility to compete."
- Not secure? "This is just FUD. The enterprise vendors ... are sowing this fear, uncertainty and doubt in their customer base to slow down adoption of public clouds."
- Loss of control? "What does it cost to build a private cloud, and how long does it take, and how many consultants and top tier ITops staff do you have to hire? ... allocate that money to the development organization, hire more developers and rewrite your legacy apps to run on the public cloud."
Then he adds his killer punch:
"The train wrecks will come as ITops discover that it's much harder and more expensive than they thought, and takes a lot longer than expected to build a private cloud. Meanwhile their developer organization won't be waiting for them."
But it's Reilly who adds the devastating coup de grace for private cloud:
"Building the private cloud that is devoid of any plan or funding to make architectural changes to today’s enterprise applications does not provide us any tangible transitional advantage, nor does it position our organization to make a move to public cloud."
In a nutshell, an enterprise that builds a private cloud will spend more, achieve less and increase its risk exposure, while progressing no further along the path towards building a cloud applications infrastructure. It's a damning indictment of the private cloud model from two CIOs top enterprise cloud architects who have practical, hands-on experience that informs what they're saying. Their message is that private cloud is a diversion and a distraction from the task of embracing cloud computing in the enterprise. It can only make sense as a temporary staging post in the context of a systematically planned transition to public cloud infrastructure.
[UPDATED 03:45am April 14: I have made small amendments to Christian Reilly and Adrian Cockcroft's job descriptions at their request. Reilly also commented via Twitter that this post "doesn't really capture the spirit my blog was written in," which I completely accept. He went on: "the point of the blog was to highlight the differences in how enterprises approach cloud versus orgs who build their business on it." Read his original post.]