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Cloud computing

  • Cloud computing = On-demand access to IT capabilities
  • Before cloud computing
    • Everything was stored and processed locally (on-premises)
    • Centralized, secluded and segmented
  • Now third party (cloud provider) stores the data.

NIST definition of cloud computing

Essential characteristics

  • On-demand self-service
    • Consumers can unilaterally provision computing capabilities
      • E.g. computing power, storage, network
    • Does not require human interaction
  • Broad network access
    • Capabilities are available and accessible over the network.
    • Via wide variety of platforms e.g. laptops, mobile phones and PDAs
  • Resource pooling
    • Uses multi-tenant model to provide resources pooled to serve multiple consumers
      • The instances (tenants) are logically isolated, but physically integrated.
      • One or multiple instances of one or multiple applications operate in a shared environment.
    • Assigns different physical and virtual resources dynamically
    • Location is abstracted to e.g. country, state or data-center
      • Exact location is unknown to user
  • Rapid elasticity
    • Feeling of "infinite" and instant scalability
    • Usually automatically
  • Measured service
    • Metering capability in an abstracting way e.g. storage, processing, bandwidth, active user accounts.
    • Resource usage can be monitored, controlled, and reported

Cloud computing service models

Infrastructure as a services (IaaS)

  • Capability for consumers to provision processing, storage, networks, and other fundamental computing resources
  • Aims to give most control over the provided hardware that runs applications
    • E.g. operating systems, storage, and networking components
  • E.g. virtual machines (EC2 in Amazon), virtual networks.

Platform as a Service (PaaS)

  • Provides capability for consumers to deploy onto managed cloud infrastructure
  • Allows consumer to use programming languages, SDKs, services, and tools supported by the provider
  • Consumer does not control or manage underlying cloud infrastructure
    • But can control deployed applications and configurations for the hosting environment
  • Provides an environment for building, testing, and deploying software applications
    • Can add features such authentication.
  • Aims to help creating an application quickly without managing the underlying infrastructure.
  • E.g. development tools, config management, and deployment platforms

Software as a Service (SaaS)

  • Software that is centrally hosted and managed for the end customer.
  • User does not control underlying cloud architecture
    • E.g. network, servers, OS, storage etc.
    • Can only control limited user-specific application configurations.

IaaS vs PaaS vs SaaS

SaaS vs IaaS vs PaaS

Identity-as-a-Service (IDaaS)

Security-as-a-Service (SECaaS)

  • Integrates security services into corporate infrastructure
  • Services include e.g. • penetration testing • authentication • intrusion detection • anti-malware • security and incident management.
  • E.g. McAfee Cloud Security

Container-as-a-Service (CaaS)

  • Container and cluster services
  • Services include e.g. • virtualized container engines • easier container and cluster management
  • Inherits features of IaaS and PaaS
  • See also container security

Function-as-a-Service (FaaS)

Separation of duties

  • Cloud computing is the ultimate in separation of duties
  • E.g.
    • The data owner is the entity accountable for the data itself
    • Data custodian is the entity responsible for access to the data
    • When a single individual becomes both the data owner and the data custodian, security issues can arise.
  • Also a countermeasure for insider attacks and social engineering attacks.

Shared responsibility

  • On-premises: you manage everything.
  • IaaS: provider manages virtualization, servers, storage and networking
  • PaaS: provider additionally manages OS, middleware and runtime
  • SaaS: provider manages everything

Cloud Deployment Models

Private cloud

  • Provisioned for exclusive use of single organization
  • May be owned/managed/operated by the organization, third party or combination
  • May be on or off premises

Public cloud

  • No local hardware to manage or keep up-to-date, everything runs on your cloud provider's hardware.
  • Services are rendered over a network
  • Provisioned for open use by the general public
  • May be owned/managed/operated by a business, academic, government or combination.
  • Exists on the premises of the cloud provider.

Community Cloud

  • Shared infrastructure between several organizations with shared concerns (e.g. compliance)
  • Not open to public
  • May be owned/managed/operated by the organization, third party or combination
  • May be on or off premises

Hybrid cloud

  • Composition of two or more cloud (private, community or public)
  • Infrastructures remain unique entities
    • but are bound by a technology allowing data and application portability.

Multi cloud

  • Multi-cloud is a environment where an organization leverages two or more cloud computing platforms to perform various tasks
  • Increases capabilities with combined offering
  • Limits data loss and downtime to a greater extent.
  • Management products include • Azure Arc • Google Anthos • AWS Outposts

Pros and cons of cloud computing

Advantages of cloud computing

  • Economical: Less infrastructure cost, less cost of ownership, fewer capital expenses
  • Operational: cost efficient, elastic, quick provisioning, automatic updates, backup and recovery...
  • Staffing: Less staff is required, less personal training
  • Security: Patch application and updates, less cost on security configurations, better disaster recovery, audit and monitoring on providers side, better management of security systems.
  • Innovation: Quick access to innovation

Disadvantages of cloud computing

  • Organizations have limited control and flexibility
  • Prone to outages and other technical issues
  • Security, privacy, and compliance issues
  • Contracts and lock-ins
  • Depends on network connections
  • Can be hard to migrate from one to another

Cloud regulations

  • FedRAMP: US regulatory effort regarding cloud computing
  • PCI DSS: Deals with debit and credit cards, but also has a cloud SIG

NIST Cloud Computing Reference Architecture

Cloud actors

  • Cloud Consumer
    • User of the cloud products and services
  • Cloud Provider
    • Delivers cloud computing based products and services
  • Cloud Auditor
    • Can conduct independent assessment of cloud services
  • Cloud Broker
    • Manages the use, performance and delivery of cloud services
    • Negotiates relationships between providers and consumers
    • Service categories
      • Service Intermediation: Improves value of a cloud service/function
      • Service Aggregation: Combining multiple services to a new one
      • Service Arbitrage: Like aggregation but services can be chosen from different vendors.
  • Cloud Carrier
    • Provides connectivity and transport of cloud services from providers to consumers.

Service Level Agreement (SLA)

  • Span across the cloud and are offered by service providers
  • Service-level agreement (SLA) is a commitment between a service provider and a client