Principles of cloud computing


What is cloud computing

Services typically offered

  • Compute power

  • Storage

  • Networking

  • Analytics

Containers - Provide a consistent, isolated execution environment for applications.

  • Standard runtime environment used to execute the app

  • Leading platform is docker

Serverless computing - Run application code without creating, configuring or maintaining a server

  • Application is broken into separate functions that run when triggered by some action

  • Only pay for the processing time used by each function as it executes

Benefits of cloud computing

Cost effective

  • No upfront infrastructure costs

  • Not buying infrastructure that isn’t fully utilised

  • Can scale up and down with demand


  • Vertical scaling (scaling up)

    • Adding more resources to a server
  • Horizontal scaling (scaling out)

    • Adding more servers


  • Automatically adding more resources to handle traffic


  • Don’t have to think about having current hardware and patches

Reliability (Microsoft responsibility)

  • Provided backup, recovery replication etc

  • Fault tolerance


  • Fully redundant datacenters

  • High availability (shared responsibility)

  • Lower customer latency

Security (shared responsibility)

  • Both physical and digital

Agility (speed to set up)

Compliance terms and requirements

Questions include:

  • How compliant is the cloud provider when it comes to handling sensitive data?

  • How compliant are the services offered by the cloud provider?

  • How can I deploy my own cloud-based solutions to scenarios that have accreditation or compliance requirements?

  • What terms are part of the privacy statement for the provider?

Economies of scale

  • Less expensive

  • More efficient

  • Pass benefits on

CapEx vs OpEx

CapEx (Capital expenditure)

  • Spend on physical infrastructure

  • Storage

  • Network

  • Backup and archive

  • Organisation continuity and disaster recovery

  • Datacentre infrastructure

  • Technical personnel


Fixed costs make prediction easier

OpEx (operational expenditure)

  • Monthly bill

  • Pay as you go

  • Get set up immediately

  • No upfront costs

  • Leasing software and customised features

  • Scaling charges based on usage/demand

  • Billing at the user or organisation level

Azure follows a consumption based model, which just has operational expenditure


Easier to respond to change

Types of cloud models

Private CloudCloud set up in own datacenter
  • Ensure the configuration is as needed
  • Control over security and compliance
  • Some initial CapEx costs
  • Limited agility
  • Require IT skills
Public cloudNo local hardware, all running on cloud provider’s hardware
  • High scalability/agility
  • Pay-as-you-go pricing
  • Not responsible for maintenance and updates of the hardware
  • Minimal technical knowledge required
  • May be security requirement that can’t be met
  • May be government policies, industry standards or legal requirements that can’t be met
  • Can’t manage hardware in the way you want to
  • May not work with legacy applications
Hybrid CloudCombining public and private clouds
  • Keep any legacy systems running
  • Flexibility to choose where things run
  • Get economies of scale from public cloud where available
  • Meet more compliance
  • Run things where it is most appropriate
Increased cost and complexity

Types of cloud services


Most flexible category; gives control over hardware.

Commonly used for:

  • Migrating workflows

  • Test and development

  • Storage, backup and recovery

Shared responsibility model - Cloud provider ensures infrastructure is working correctly, customer makes sure the service they are using is configured correctly, is up to date and is available to users.


Provides an environment for building, testing and deploying software applications. Don’t have to manage infrastructure. Commonly used for:

  • Development framework

  • Analytics or business intelligence


Only responsible for data+access

Access in Azure via marketplace

Pay-as-you-go pricing

Users pay for software they use on a subscription model

Cost and Ownership

Upfront costsNone, pay for consumptionNone, pay for consumptionNone, pay subscription
User ownershipUser responsible for software, OS, middleware and applicationsUser responsible for development of applicationsUsers just use software
Cloud provider ownershipInfrastructure is available to userOS, Network and serviceProvision, management and maintenance of application software.

5 Layer Diagram