ITAPP

• Infrastructure as a Service (IaaS)

  Rent virtualized infrastructure and build up your own IT system among those resources, which may be fully controlled
• Platform as a Service (PaaS)


  Directly develop your IT system through one cloud platform, and do not care about any lower-level resource management
• Software as a Service (SaaS)


  Directly use some existed IT system solutions, which were provided by some cloud application service provider, without knowing any detail technique about how these service was achieved
• SaaS


  • Delivers software applications over the internet on a subscription basis
  • Users can access and use applications directly through a web browser or APIs
  • The provider hosts and manages the underlying infrastructure, application, and data
  • Users can typically customize certain aspects of the application to fit their needs
• Examples of SaaS


  • Salesforce
  • EyeOS
  • Microsoft Office 365
  • Google Apps (e.g., Gmail, Google Docs, Google sites, …etc)
  • Google Workspace
• Capability provided to the consumer in SaaS

  • Use the provider's applications running on a cloud infrastructure
  • The applications are accessible from various client devices through a thin client interface such as a web browser (e.g., web-based email)
  • The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings
• Web 2.0


  • Viewing the Internet as a computing platform
  • Running interactive applications through a web browser
  • Leveraging interconnectivity and mobility of devices
  • Enhanced effectiveness with greater human participation
• Properties provided by Internet

  • Accessibility
  • Portability
• Types of web-based applications

  • General Applications – Applications which are designed for general propose, such as office suit, multimedia and instant message
  • Business Applications – Application which are designed for business propose, such as ERP, CRM and market trading system
  • Scientific Applications – Application which are designed for scientific propose, such as aerospace simulation and biochemistry simulation
  • Government Applications – Applications which are designed for government propose, such as national medical system and public transportation system service
• Web Portal


  • Apart from the standard search engine feature, web portals offer other services such as e-mail, news, stock prices, information, databases and entertainment
  • Portals provide a way for enterprises to provide a consistent look and feel with access control and procedures for multiple applications and databases, which otherwise would have been different entities altogether
• Examples of web portals


  • iGoogle
  • MSNBC
  • Netvibes
  • Yahoo!
• SaaS


  The finished applications that you rent and customize
• Users of SaaS


  • End Customers
• Characteristics of SaaS


  • On-demand service
  • Pay per use of application software to users
  • Independent platform
  • Don't need to install the software on your PC
  • Runs a single instance of the software
  • Available for multiple end users
  • Cloud computing cheap
  • Computing resources managed by vendor
  • Accessible via a web browser or lightweight client applications
• Pros of SaaS


  • Universally accessible from any platform
  • No need to commute, you can work from any place
  • Excellent for collaborative working
  • Vendor provides modest software tools
  • Allows for multi-tenancy
• Cons of SaaS


  • Portability and browser issues
  • Internet performance may dictate overall performance
  • Compliance restrictions
• Platform as a Service (PaaS)


  • Offers a platform for developing, testing, and deploying applications
  • Users can focus on application development without worrying about infrastructure management
  • PaaS providers manage the underlying infrastructure, including servers, storage, and networking
  • Developers can leverage pre-configured environments, development frameworks, and deployment tools
• Examples of PaaS providers


  • Heroku
  • Google App Engine
  • Microsoft Windows Azure
  • Hadoop
  • AWS Elastic Beanstalk
• Capability provided to the consumer in PaaS


  • Deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages and tools supported by the provider
  • The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly application hosting environment configurations
• Runtime Environment


  • Collection of software services available, usually implemented by a collection of program libraries
  • Common properties: Manageability and Interoperability, Performance and Optimization, Availability and Reliability, Scalability and Elasticity
• Users of PaaS


  • Developers
• Components of PaaS runtime environment

  • Programming language execution environment
  • Operating system
  • Web server
  • Database
• PaaS model


  You made data and the application resources; all other resources are managed by the vendor
• Pros of PaaS


  • Cost effective rapid development (it's scalable)
  • Faster market for developers
  • Easy deployment of web applications
  • Private or public deployment is possible
• Cons of PaaS


  • Developers are limited to the providers' languages and tools
  • Migration issue – such as the risk of vendor lock-in
• Infrastructure as a Service (IaaS)

  • Provides virtualized computing resources over the internet
  • Users have control over the operating systems, storage, and networking components
  • They can provision and manage virtual machines (VMs), storage, and networks according to their requirements
• Examples of IaaS providers

  • AWS EC2
  • Eucalyputs
  • OpenNebula
  • Azure Virtual Machines
  • Google Compute Engine
• Capability provided to the consumer in IaaS

  • Provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications
  • The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, deployed applications, and possibly limited control of select networking components
• Properties supported by virtualization technique in IaaS

  • Manageability and Interoperability
  • Availability and Reliability
  • Scalability and Elasticity
• System Monitoring Interface in IaaS

  • Monitor virtual machine states such as CPU loading, memory utilization, IO loading and internal network loading
  • Monitor virtual storage states such as virtual space utilization, data duplication and storage device access bandwidth
  • Monitor virtual network states such as virtual network bandwidth, network connectivity and network load balancing
• Users of IaaS


  • SysAdmins
• IaaS


  • Offers the computing architecture and infrastructure in a virtual environment so that multiple users can access them
  • Resources include: data storage, virtualization, servers and networking
  • Most vendors are responsible for managing the above four resources
  • User will be responsible for handling other resources such as applications, data, runtime, and middleware
• Pros of IaaS


  • The cloud provides the infrastructure
  • Enhanced scalability – dynamic workloads are supported
  • IaaS is flexible
• Cons of IaaS


  • Security issues
  • Network and service delays
• Public Cloud


  • Services are provided over a public network and available to anyone who wants to use them
  • It is a cost-effective option for businesses and individuals looking for scalability and flexibility
  • Public cloud providers, such as AWS, Azure, and GCP, offer a wide range of services accessible to the general public
• Private Cloud


  • Infrastructure is dedicated to a single organization and may be located on-premises or off-premises
  • Private cloud environments are designed to meet specific security, compliance, or performance requirements
  • They offer enhanced control, customization, and privacy but require significant upfront investment
• Hybrid Cloud


  • Combines public and private cloud environments, allowing for flexibility and data sharing between the two
  • Organizations can leverage the benefits of both public and private clouds, ensuring optimal resource allocation
  • Hybrid cloud deployments enable workload portability and seamless integration between different environments
• Community Cloud


  • Infrastructure and services are shared among a specific community or group of organizations
  • It caters to the needs of a particular community, such as government agencies, educational institutions, or research organizations
  • Community cloud provides a cost-effective solution while addressing specific requirements and compliance standards of the community

  
• Common cloud computing use cases

  • Data Storage and Backup: Store and back up large amounts of data securely
  • Software Development and Testing: Rapidly create and deploy applications in a scalable environment
  • Web and Mobile Applications: Host web and mobile applications in the cloud for global accessibility
  • Big Data Analytics: Process and analyze vast amounts of data using cloud resources
  • Disaster Recovery: Maintain data backups and recovery plans in the cloud for business continuity
• Cloud architecture


  • Refers to the design and structure of cloud computing environments, including the arrangement of components and the relationships between them
  • It involves various elements that work together to deliver cloud services and ensure reliability, scalability, and security