Cloud Concepts

Definition

  • Delivery of computing services over the internet (common IT infrastructure such as virtual machines, storage, databases, and networking).
  • Cloud services also expand the traditional IT offerings to include things like Internet of Things (IoT), machine learning (ML), and artificial intelligence (AI).
  • It allows to move capital expenditure (servers, datacenters, etc) into operational expenditure (cloud costs).

Benefits

  • High availability: Always available (SLA)
  • Scalability:
    • Vertical: Ease to add more power to machines
    • Horizontal: Ease to add more machines
  • Reliability: Decentralized, globally distributed
  • Predictability: Constant performance and costs
  • Security: Different levels of access, built in protection
  • Governance: Ease to implement compliance
  • Manageability: Ease to add/delete resources and interact with infrastructure

Models

3 different models:

  • Public Cloud:
    • Build controlled and maintained by a third party
    • Available to the public
  • Hybrid Cloud:
    • Use private and public clouds interconnected
  • Private Cloud:
    • Cloud used by a single entity
    • On premises
    • Offers total control
    • More cost and complexity

Service Types:

Cloud providers distinguish 3 types of service. Each service place responsibility to the provider or the customer side (Shared responsibility model). These are:

  • IaaS:
    • Infrastructure as a service
    • Most responsibility to the customer
    • Provider maintains and manages physical infrastructure
    • Examples include VM services, virtual networks, etc.
  • PaaS
    • Platform as a service
    • Middleground
    • Provider additionally maintains OS, dev tools, etc.
    • Examples like Azure app services, AKS
  • SaaS
    • Software as a service
    • Complete managed solution
    • Examples include Managed dbs

The different responsibilities for each service type are shown below

srm srm