Contrary to the common private-cloud thinking, where multiple VMs run on each physical host, the "zCloud" has one virtual instance per physical server. The cloud was built on several thousand x86 servers using XenServer and KVM hypervisor technology. The next step was to build its own private cloud.
The approach worked, but, as Leinwand put it, Zynga was only replacing capital expenses with operating ones.
In 2009, when FarmVille led to the inflection point of not being able to provision capacity fast enough, the company moved to public cloud, using VM instances through Amazon Web Services' Elastic Compute Cloud (EC2) and automating provisioning. Leinwand delivered an opening keynote at this Thursday's DatacenterDynamics conference in San Francisco, in which he explained how the company scales its infrastructure. "We couldn't continue to grow traditional retail (or) wholesale data centers fast enough," he said. Zynga's infrastructure team has found itself in a situation where growth of its user base quickly outpaced provisioning time of infrastructure components, including data center space, power and cooling, CentOS servers and internet transit network capacity. Zynga CTO Allan Leinwand said FarmVille, one of the social-gaming company's most popular products, grew to 25m daily active users within five months of its launch. While most companies have the luxury of taking their time to evaluate the viability of using cloud infrastructure services before they implement them, Zynga had to go to the cloud because it had no other choice.