CLOUD COMPUTING (1ST PART)

• Cloud computing


  Delivery of computing services over the internet, including storage, processing power and software applications
• Cloud computing


  • Allows users to access resources and services on-demand, without the need for physical infrastructure or local servers
• NIST definition of cloud computing

  A model for enabling convenient, on demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, application, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction
• Wikipedia definition of cloud computing

  Internet-based computing, whereby shared resources, software, and information are provided to computers and other devices on demand, like the electricity grid
• Whatis.com definition of cloud computing


  The name cloud computing was inspired by the cloud symbol that's often used to represent the Internet in flowcharts and diagram. Cloud computing is a general term for anything that involves delivering hosted services over the Internet

  
• Berkeley definition of cloud computing

  Cloud Computing refers to both the applications delivered as services over the internet and the hardware and systems in the datacenters that provide those services. The services themselves have long been referred to as Software as a Service (SaaS), so we use that term. The datacenter and software is what we will call a Cloud. When a Cloud is made available in a pay-as-you-go manner to the public… The services being sold is Utility Computing

  
• Buyya definition of cloud computing

  A Cloud is a type of parallel and distributed system consisting of a collection of interconnected and virtualized computers that are dynamically provisioned and presented as one or more unified computing resources based on service-level agreements established through negotiation between the service provider and consumers. Cloud computing is a paradigm of computing, a new way of thinking about IT industry bot not any specific technology

  
• Central ideas of cloud computing

  • Utility Computing
  • SOA – Service Oriented Architecture
  • SLA – Service Level Agreement

  
• Properties and characteristics of cloud computing

  • High scalability and elasticity
  • High availability and reliability
  • High manageability and interoperability
  • High accessibility and portability
  • High performance and optimization

  
• Enabling techniques of cloud computing

  • Hardware virtualization
  • Parallelized and distributed computing
  • Web service
• Utility computing


  • Scalability and elasticity (dynamic provision, multi-tenant design)
  • Availability and reliability (fault tolerance, system resilience, system security)
  • Performance and optimization (parallel processing, load balancing, job scheduling)
  • Accessibility and portability (uniform access, thin client)
  • Manageability and interoperability (control automation, system monitoring, billing system)
• Benefits of cloud computing

  • Cost Saving: Pay for what you use, with no upfront infrastructure costs
  • Scalability: easily scale resources up or down based on demand
  • Flexibility: access resources and applications from anywhere with an internet connection
  • Reliability: cloud providers typically offer high uptime and data redundancy
  • Collaboration: enable seamless collaboration and data sharing among teams
• Fault tolerant system


  Enables a system to continue operating properly in the event of the failure of some of its components, with the decrease in operating quality proportional to the severity of the failure
• Characteristics of fault tolerant systems

  • No single point of failure
  • Fault detection and isolation to the failing component
  • Fault containment to prevent propagation of the failure
  • Availability of reversion modes
• Availability


  The degree to which a system, subsystem, or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown time. Cloud systems usually require high availability, e.g. "Five nines" system would statistically provide 99.999% availability
• Reliability


  The ability of a system or component to perform its required functions under stated conditions for a specified period of time
• Characteristics of cloud computing

  • On-demand Self-Service: Users can provision resources and services as needed, without requiring human interaction with service providers
  • Broad Network Access: Services are accessible over the internet via standard protocols and devices
  • Resource Pooling: Computing resources are pooled together to serve multiple users, allowing for efficient utilization and scalability
  • Rapid Elasticity: Resources can be scaled up or down quickly to meet changing demands
  • Measured Service: Cloud service usage is measured, monitored and billed based on actual consumption
• Cloud deployment models