Chapter 2 Flashcards
Chapter 2 focuses on the architecture and platforms of cloud computing, primarily classifying clouds by service model and deployment mode (8 cards)
Cloud classification by service model
Based on the service model offered. Represents a specific, pre-packaged combination of IT resources.
Three common layers/models: IaaS, PaaS, SaaS
Infrastructure-as-a-Service (IaaS)
Bottom layer of the service model stack.
Provides IT infrastructure as a service (servers, storage, networking).
Offers essential computing and storage capabilities based on hardware resources.
Provides access to fundamental resources like physical/virtual machines, virtual storage, IP addresses, VLANs.
Cloud consumer has a high level of control and responsibility over configuration and utilization.
Characteristics: Web access to resources, Elasticity, Dynamic Scaling, Preconfigured VMs, Metered Services (pay per usage).
Benefits: Full control through administrative access to VMs, Flexible renting of hardware, Portability and interoperability with legacy apps.
Challenges: Data erasure practices, Compatibility with legacy security, Robustness of VM level isolation.
Examples: Amazon Web Services (AWS), Microsoft Azure, Google Compute Engine (Not explicitly listed as IaaS examples but these providers offer IaaS as noted elsewhere).
Topic/Concept: Platform-as-a-Service (PaaS)
Middle layer.
Provides an internet-based application development environment.
Includes APIs, operating platforms, and resources for the entire application lifecycle (development, testing, deployment).
Allows developers to focus on coding rather than managing infrastructure.
Characteristics: All in one development platform, Web-based UI, Collaborative platform, Diverse client tools.
Examples: Heroku, Google App Engine (Not explicitly listed as PaaS examples but these providers offer PaaS as noted elsewhere).
Software-as-a-Service (SaaS)
Top layer.
Delivers software applications over the Internet, accessible via a standard web browser.
Provider handles all software and hardware maintenance.
Typically offered for free or on a subscription/pay-per-use basis.
Eliminates the need for local installation and maintenance.
Catters to both individual users and enterprises.
Characteristics: One-to-many model (single instance serves many), Multidevice support, Better scalability (leverages PaaS/IaaS), High availability, API integration.
Benefits: Scalable and efficient, Centralized management and data, Multitenant solutions, Provider manages platforms.
Challenges: Network dependent, Browser-based risks, Multitenant solutions (can be both benefit and challenge), Lack of portability between SaaS clouds.
Examples: Google Calendar, Gmail (for individuals). Billing systems, Help desk apps, CRM tools (for enterprises). Salesforce (listed as a provider).
Private Cloud
Cloud infrastructure exclusively used by a single organization.
Can be on-premise or externally hosted by a third party.
Organization has full control over resources and configuration.
Dedicated environment not shared with other entities.
Favored by enterprises with sensitive data or stringent regulatory requirements.
Benefits: Enhanced Security and Privacy, greater Customization. Offers control, enhanced security, privacy, and customization.
Disadvantages: Higher costs (initial investment and ongoing), Limited scalability (compared to public cloud).
Public Cloud
Owned and operated by a third-party provider.
Shared among multiple tenants.
Highly scalable.
Cost-effective, available on-demand with pay-per-use model.
Benefits: Cost-effectiveness, Scalability and Elasticity, High Availability, Highly reliable.
Disadvantages: Security Concerns (shared by multiple orgs), Limited Customization. Organizations must trust provider’s security measures.
Hybrid Cloud
A combination of two or more different cloud models (e.g., private and public) linked together.
Allows organizations to leverage benefits of both.
Data/applications can be shared between the models.
Often uses private cloud for sensitive workloads and public cloud for less sensitive, scalable tasks.
Beneficial for businesses with legacy systems needing integration.
Benefits: Flexibility (choose workload placement), Scalability (similar to public while keeping private control/security), Improved Disaster Recovery, Cost-efficient.
Disadvantages: Complexity (management/integration), Cost (integration, data transfer, specialized personnel), Networking issues, Security compliance, Infrastructure dependency.
Community Cloud
Shared infrastructure among a group of organizations with common interests, requirements, or goals.
Offers a collaborative platform.
Organizations share infrastructure, resources, and management responsibilities.
Typically utilized by government agencies, educational institutions, industry groups.
Focus on collaboration and shared governance.
Disadvantages: Shared governance challenges, Limited Scalability (less flexible than public), Security Concerns (sharing infra, potential breaches/conflicts)
