UC Berkeley Clouds Above the clouds : A Berkeley View of Cloud Computing Electrical Engineering and Computer Sciences University of California at Berkeley Technical Report No. UCB/EECS February 10, 2009

Executive Summary Cloud Computing, has the potential to transform a large part of the IT industry, making software even more attractive as a service and shaping the way IT hardware is designed and purchased. Cloud Computing refers to both the applications delivered as services over the Internet and the hardware and systems software in the datacenters that provide those services.

Executive Summary(contd.) The services themselves have long been referred to as Software as a Service (SaaS). The datacenter hardware and software is what we will call a Cloud. When a Cloud is made available in a pay-as-you- go manner to the general public, we call it a Public Cloud; the service being sold is Utility Computing.

Executive Summary(contd.) We use the term Private Cloud to refer to internal datacenters of a business or other organization, not made available to the general public. Thus, Cloud Computing is the sum of SaaS and Utility Computing, but does not include Private Clouds.

Executive Summary(contd.) From a hardware point of view, three aspects are new in Cloud Computing. 1.The illusion of infinite computing resources available on demand, thereby eliminating the need for Cloud Computing users to plan far ahead for provisioning. 2.The elimination of an up-front commitment by Cloud users, thereby allowing companies to start small and increase hardware resources only when there is an increase in their needs.

Executive Summary(contd.) 3. The ability to pay for use of computing resources on a short-term basis as needed (e.g., processors by the hour and storage by the day) and release them as needed, thereby rewarding conservation by letting machines and storage go when they are no longer useful.

What is Cloud Computing?

Why become a Cloud Provider? 1. Make a lot of money. 2.Leverage existing investment. 3.Defend a franchise. 4.Attack an incumbent. 5.Leverage customer relationships 6.Become a platform

New Application Opportunities Mobile interactive applications Parallel batch processing The rise of analytics Extension of compute-intensive desktop applications “Earthbound” applications

Obstacles for Cloud Computing Number 1 Obstacle: Availability of a Service Number 2 Obstacle: Data Lock-In Number 3 Obstacle: Data Confidentiality and Auditability Number 4 Obstacle: Data Transfer Bottlenecks Number 5 Obstacle: Performance Unpredictability Number 6 Obstacle: Scalable Storage

Obstacles (contd.) Number 7 Obstacle: Bugs in Large-Scale Distributed Systems Number 8 Obstacle: Scaling Quickly Number 9 Obstacle: Reputation Fate Sharing Number 10 Obstacle: Software Licensing

Conclusions and Implications for the Future Applications Software of the future will likely have a piece that runs on clients and a piece that runs in the Cloud. Infrastructure Software of the future needs to be cognizant that it is no longer running on bare metal but on virtual machines. Moreover, it needs to have billing built in from the beginning, as it is very difficult to retrofit an accounting system.

Conclusions (contd.) Hardware Systems of the future need to be designed at the scale of a container (at least a dozen racks) rather than at the scale of a single 1U box or single rack, as that is the minimum level at which it will be purchased.