Intro of Cloud Computing

cloud_computing

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1 What is cloud computing

Cloud computing is a new computing paradigm, involving data and/or computation outsourcing, with

    1. Infinite and elastic resource scalability
    2. On demand “just-in-time” provisioning
    3. No upfront cost … pay-as-you-go

2 Advantages

For clients:

• No upfront commitment in buying/leasing hardware
• Can scale usage according to demand
• Barriers to entry lowered for startups

For providers:

• Increased utilization of datacenter resources

3 Cloud computing means selling “X as a service”

IaaS: Infrastructure as a Service

• Selling virtualized hardware
• e.g. EC2

PaaS: Platform as a service

• Access to a configurable platform/API
• e.g. Google AppEngine

SaaS: Software as a service

• Software that runs on top of a cloud
• e.g. Google Docs

4 Modalities

• Hosted Applications and services
• Pay-as-you-go model
• Scalability, fault-tolerance, elasticity, and self-manageability
• Very large data repositories
• Complex analysis
• Distributed and parallel data processing

5 Cloud is often a collection of a large number of virtual devices such as VMs and virtualized disks

6 Virtual Machine

6.1 Isolation: Secure Multiplexing, Strong Gurantee, Performance Isolation

6.2 Encapsulation: Entire VM is a File, Snapshot and Clone, Easy Content Distribution

6.3 Compatibility: Hardware-Independent, Create-once-run-anywhere, Legacy VMs