Cloud Computing

• On-premise IT infrastructure


  IT infrastructure deployed by companies on their own premises rather than in vendors' data centres
• Challenges with on-premise IT infrastructure

  • Investment required to acquire the infrastructure is a barrier for small businesses
  • Maintaining and upgrading infrastructure over time to ensure it remains reliable and up-to-date poses a significant challenge
• Type 1 server virtualization


  Virtualization technology where the hypervisor operates directly on the hardware of a physical server, bypassing the operating system

  
• Type 2 server virtualization


  Virtualization technology where a hypervisor operates within the host operating system of a physical server
• Cloud computing (NIST definition)

  A model for enabling convenient, on-demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction

  
• Characteristics of cloud computing

  • On-demand self-service
  • Broad network access
  • Resource pooling
  • Rapid scalability
  • Measurable service

  
• Cloud computing service models

  • Software as a Service (SaaS)
  • Platform as a Service (PaaS)
  • Infrastructure as a Service (IaaS)
• Cloud computing deployment models

  • Private cloud
  • Community cloud
  • Public cloud
  • Hybrid cloud
• Cloud computing


  Technology that allows companies to access computing resources, such as servers, storage, applications, and services, via the internet on an as-needed basis
• On-demand self-service in cloud computing

  • Allows users to provision and manage computing resources independently, without needing assistance from the cloud provider
• Broad network access in cloud computing

  • Enables cloud resources to be accessed from anywhere using any internet-connected device
• Resource pooling in cloud computing

  • Multiple users can share the same computing resources, enabling cloud providers to achieve economies of scale and provide access to resources customers may not be able to afford individually
• Rapid scalability in cloud computing


  • Enables cloud resources to be rapidly and easily scaled up or down in response to changes in demand
• Measurable service in cloud computing

  • Enables cloud providers to measure and monitor the usage of resources and furnish customers with detailed usage reports
• Benefits of cloud computing

  • Cost savings
  • Scalability
  • Flexibility
  • Backup and Disaster Recovery
  • Security
  • Innovation
• Cloud computing eliminates the need to purchase and maintain expensive IT hardware and software
• Cloud computing allows organizations to rapidly adjust their IT resources in response to changes in demand
• Cloud computing enables organizations to access their IT resources from anywhere and at any time, enhancing collaboration
• Cloud computing automatically backs up data to ensure business continuity in the event of a disaster
• Cloud computing enhances data security, as cloud providers invest significantly in security measures
• Cloud computing allows organizations to experiment with new technologies rapidly and safely, reducing the time to market for new products and services
• Region


  Separate geographic area in AWS consisting of multiple, physically separated availability zones connected with low latency, high throughput and redundant networking
• Availability Zone (AZ)


  Consist of one or more data centers, each with redundant power and networking
• Data center


  Houses between 50,000 and 80,000 physical servers designed to process and manage a large amount of data, operates independently of others
• IP address


  Unique identifier for a computer in a network, IPv4 is 32-bit, IPv6 is 128-bit

  
• The purpose of an IP address is to enable communication between devices in a network

  
• Classless Inter-Domain Routing (CIDR)

  1. CIDR block is a collection of IP addresses that share the same network prefix and number of bits

  2. Number of possible IP addresses = 2^(32-number of fixed bits)

  
• Virtual Private Cloud (VPC)


  Isolated network segment that facilitates the provision of AWS resources, network configuration can be customized

  
• VPC


  • Associated with a CIDR block of 16 to 65,536 unique IP addresses
  • 5 IP addresses reserved for specific purposes in a CIDR block

  
• Elastic IP address


  Static and public IPv4 address that can be associated with any instance or network interface in a VPC, can be reassigned if an instance fails
• Route table


  Set of rules defining how data traffic is routed in a network, each subnet is associated with a specific route table

  
• Network Address Translation (NAT) gateway


  Allows instances in a private subnet to access the Internet while preventing the Internet from accessing these instances
• An internet gateway (igw) enables communication between resources in a VPC and the internet

  
• IaaS


  The capability provided to the consumer to 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, and deployed applications; and possibly limited control of select networking components (e.g., host firewalls).

  
• IaaS


  • Amazon Elastic Compute Cloud (Amazon EC2), Rackspace, Google Compute Engine
• IaaS (concept)


  Compared to making a cake, an IaaS provider can be compared to a kitchen rental company that provides ingredients, ovens and tools for cake making. This facility offers the flexibility to customize the quantity of ingredients, the size of the oven and the type of tools used.
• IaaS


  • Offers virtual machines (VMs), databases, storage and other resources for building cloud applications
  • Provides the flexibility to customize the number of resources, computing power, storage capacity and choice of operating system and software

  
• PaaS


  The capability provided to the consumer to deploy onto the cloud infrastructure consumer created or acquired applications created using programming languages, libraries, services, and tools supported by the provider.
• PaaS


  • AWS Elastic Beanstalk, Microsoft Azure, Google App Engine
• PaaS (concept)


  Compared to making a cake, a PaaS provider can also be compared to a kitchen rental company that provides ready-made ingredients, ovens and tools. These ready-made ingredients enable users to bake cakes quickly and easily without having to worry about preparing the ingredients.