3. What is the cloud?(Cont.)

5. 5 TIME IT CAPACITY Actual Load Allocated IT-capacities Too Much Power Not Enough Power Load Forecast Why we need cloud?

6. Actual Load Capacity on Demand Lower Capex No capital laying idle No screaming customers Knob goes up... And... down TIME IT CAPACITY Load Forecast Why we need cloud?

7. Usage Compute Time Average Inactivity Period ON ＆ OFF 负载（例如批处理作业） 超过供应能力是浪费 响应市场不灵活 Compute Time Average Usage Compute Time Compute Time Average Usage

8. Software-as-a-Service “SaaS” Platform-as-a-Service “PaaS” Infrastructure-as-a-Service “IaaS”

9. Packaged Software Storage Servers Networking O/S Middleware Virtualization Data Applications Runtime You manage Infrastructure (as a Service) Storage Servers Networking O/S Middleware Virtualization Data Applications Runtime Managed by vendor You manage Platform (as a Service) Managed by vendor You manage Storage Servers Networking O/S Middleware Virtualization Applications Runtime Data Software (as a Service) Managed by vendor Storage Servers Networking O/S Middleware Virtualization Applications Runtime Data

10. 存储 服务器 网络 操作系统 中间件 虚拟化 数据 应用 运行时组件 IaaS 存储 服务器 网络 操作系统 中间件 虚拟化 数据 应用 运行时组件 客户负责客户负责 SaaS 存储 服务器 网络 操作系统 中间件 虚拟化 应用 运行时组件 数据 PaaS 存储 服务器 网络 操作系统 中间件 虚拟化 应用 运行时组件 数据 客户负责客户负责 客户负责

11. The keyword: Virtualization. Providers of IaaS : Amazon Rackspace ServerPath VMWare

12. Amazon Web Services Infrastructure Services: Amazon Cloudwatch: Autoscaling Amazon Cloudfront: content delivery network (CDN) Amazon Route 53: highly available and scalable DNS Amazon Virtual Private Cloud (VPC) : secure bridges into on-premises computing Elastic Load Balancing: distributing incoming application traffic SQS: Simple Queue Service for messaging SNS: Simple Notification Service for alerting

13. Mosso/The Rackspace Cloud Infrastructure Services: Content Delivery Network (CDN) Simple Load Balancing using virtualized server to provide load balancing

14. GoGrid Infrastructure Services: Content Delivery Network (CDN) with a boasted 18 points of presence on 4 continents F5 Hardware Load Balancing Data Center specific provisioning Auto scaling with Vertical RAM Scaling and more features

16. VMware Infrastructure:

17. How is it different from traditional hosting services: In cloud, the billing is on hourly or monthly basis, not fixed amount. Cloud is elastic in nature, not fixed resources. In cloud, you can scale up and down within a minutes, not a month.

23. Software as a Service(SaaS) Software as a Service is a term used to describe software that is deployed over the internet and the provider licensing applications to subscribers as a 'service-on-demand'. Typically the services are provided in a 'pay-as- you-go' model with typically payments charged on a monthly basis based on the number of users or services consumed.