Cloud Computing

CAPEX

Capital Expenses (CAPEX) is money spent to buy fixed assets. It cannot be deducted in the year of spending and has to be capitalized (e.g. hardware)

OPEX

Operational Expenses (OPEX) are the sum of all day-to-day, ongoing expenses for operations (e.g. license fees, maintenance, etc).

TCO

Total Cost of Ownership (TCO) = CAPEX + OPEX

Considerations

ICT capacity consumption models:

• Stable capacity
• Scheduled increase in capacity
• Scheduled increase in capacity
• Periodic bursting
• Predictable bursting
• On and Off - Inactive periods

Usually we see the model of periodic bursting which makes it hard to plan for optimal capacity / cost.

Planned capacity vs actual use:

• too much capacity => waste
• too little capacity => customer dissatisfaction

Principles

• On-demand self-service: A consumer can provision computing capabilities automatically and without human interaction
• Broad network access: Accessibility over the network and through standard protocols
• Resource pooling (multi-tenancy): Resources are pooled to serve multiple consumers and the consumer has no control or knowledge of the exact location of the provided resource
• Rapid elasticity: Resources can be elastically provisioned and released i.e. scaled out an in
• Measured service (pay-as-you-go): Resources are automatically controlled and optimized and usage can be monitored, controlled and reported transparently

Service Models

End Users:

• Software as a Service (SaaS): Applications running on cloud infrastructure by providers and for consumers to access

Application Developers:

• Function as a Service (FaaS): Server-less computing - provided code is run and charged for by a cloud operator
• Platform as a Service (PaaS): Deploy applications onto cloud infrastructure without having to manage it

Network Architects:

• Infrastructure as a Service (IaaS): Provisioning of processing, storage, networks and other computing resources without having to manage the underlying cloud infrastructure/physical hardware

Deployment Models

• Private cloud: Provisioned for exclusive use by a single organization
• Community cloud: Provisioned for exclusive use by a specific community of consumers with shared concerns
• Public cloud: Provisioned for open use by the general public
• Hybrid cloud: Composition of two or more distinct cloud infrastructures, bound together to enable storage and compute portability