The Origins and Future of Distributed Computing and Clouds - The Practice of Cloud System Administration - page 468

Technology
The technology that drives cloud computing itself is the ability to segment infrastructure
suchthatone“tenant”cannotinterferewithanother.Thisrequiresnetworkingtechnologies
that allow segmenting computers from each other at a very fine granularity such as pro-
grammable VLANs and software-defined networks. It requires the ability to partition one
large machine into many smaller ones—that is, virtualization technology. It requires con-
trolpanels,APIs,andvariousself-serviceadministrationcapabilitiessothatcustomerssup-
port themselves and do not add considerable labor cost to datacenter operations. It requires
storage and other services to attract customers.
Amazon was the first company to develop such a system. Amazon Elastic Compute
Cloud (Amazon EC2) was the first major company to rent virtual machines on its infra-
structure to subsidize its cost. The term “elastic” comes from the fact that this approach
makesitsofasttoexpandandcontracttheamountofresourcesbeingused.Oneofthemost
attractive features is how quickly one can spin up new machines. Even more attractive is
how quickly one can dispose of machines when they aren't needed. Suppose you needed
1000 machines for a month-long web advertising campaign. It would be an arduous task
to set up that many machines yourself and difficult to get rid of them a month later. With
EC2, you can spin them all up with a mouse click or a few API calls. When the campaign
is over, releasing the machines is just as simple.
Such “tenant” systems are just getting started. We are just now beginning to understand
these new economics and their ramifications.
B.6 Conclusion
Thegoalofthisappendixwastoexplainthehistoryoftechnologiesusedforprovidingweb
services. The techniques described here form the basis for the platform options introduced
in Chapter 3 , the web architectures presented in Chapter 4 , and the scaling and resiliency
techniques described in Chapters 5 and 6 . The other chapters in this topic reflect the oper-
ational practices that make all of the above work.
The economics of computing change over time. Faster and more reliable computing
technologyhadasuper-linearcostcurveinthepre-webandfirstweberas.Thesecondweb
era was enabled by linear cost curves. Cloud computing gives us sub-linear cost curves.
These changes happened by taking advantage of commoditization and standardization,
shiftingtoopensourcesoftware,buildingmorereliabilitythroughsoftwareinsteadofhard-
ware, and replacing labor-intensive operations with more software.
Every order-of-magnitude improvement in the cost of computing enables a new era of
applications, each of which was unimaginable just a few years before. Could the person