With the gradual maturity of the network, the total number of people in the network has increased from 16 million in 1995 to more than 3 billion at the end of 2015. Along the application requirements for scale and performance have also increased significantly, the technology of the “client/server” era is no longer suitable for the needs of the Internet giant, both in terms of technical feasibility and cost performance.

Therefore, Internet companies have begun to find another way. With its technical expertise and academic progress, Google, Facebook and Amazon have defined a new class of infrastructure. Such infrastructure has the following characteristics: scale scalable, programmable, usually open source, and low unit cost. A series of platforms or tools including Linux, KVM, Xen, Docker, Kubernetes, Mesos, MySQL, MongoDB, Kafka, Hadoop and Spark have formed a significant era of cloud computing, we call this the second stage. You can think of humans have the ability to breed wild animals on any piece of land, and to allow more people to enjoy these prey at any time.