Overview of Clod Service Models

IaaS (基礎設施即服務)

是一種提供基礎計算、網絡和存儲的雲計算形式，以按需付費的方式通過網路向消費者提供資源 客戶 - 創建或配置虛擬機(VM)在他們選擇的雲提供商提供的區域 雲提供商 - 通常為客戶提供跟踪(track)和監控(monitor)性能的能力，及管理災難恢復(disaster recovery)

Key components

• Physical data centers
• Compute
• Network
• Storage

Some concern

• Lack of transparency
• Dependency on a third party

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PaaS (平台即服務)

是一種雲計算模型 為客戶提供完整的開發(Develop)、部署平台(Deploy)、管理(Manage)和運行(Run)由他們創建或從第三方獲得的應用程式

Services

• Servers
• Networks
• Storage
• Operating system
• Application runtimes
• APIs
• Middleware
• Databases

Essential Characteristics of Paas

• High level of abstraction
• Support services and APIs
• Run-time environments
• Rapid deployment mechanisms
• Middleware capabilities

Use Cases

• API development and management
• Internet of Things(IoT)
• Business analytics/intelligence
• Business Process Management(BPM)
• Master data management(MDM)

Advanges of PaaS

• Scalability
• Faster time to market
• Greater agility and innovation

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SaaS (軟體即服務)

SaaS 為用戶提供對服務提供商基於雲的軟體的訪問。用戶只需訪問雲上的應用程式，而雲提供商維護應用程式的基礎設施、平台、數據、應用程式代碼、安全性、可用性和性能。

Services

• Email and Collaboration (EX:gmail or office365)
• Customer Relationship Management(CRM)
• Human Resource Management
• Financial Management

Key Characteristics

• Mutitenant Architecture
• Manage Privileges and Monitor Data
• Security, Compliance, Maintenance
• Customize Applications
• Subscription Model
• Scalable Resources

Key Benefits

• Greatly reduce the time from decision to value
• Increase workforce productivity and efficiency
• Spread out software costs over time

Use Cases

• Reduce on-premises IT infrastructure and capital expenditure
• Avoid ongoing upgrades, maintenance, and patching
• Run application with minimal input
• Manage websites, marketin, sales, and operations
• Gain resilience and business continuity of the cloud provider

Concerns

• Data ownership and data safety
• Third party maintains business-critical data
• Needs goof internet connection