Cloud Computing
Service delivery model over the internet (cloud). This includes but is not limited to
- compute power meaning servers such as windows, linux, hosting environments, etc.
- storage like files and/or databases
- networking in azure but also outside when connecting to your company network
- analytics services for visualization and telemetry data
Key concepts
- scalability is the ability to scale, so allocate and deallocate resources at any time
- elasticity is the ability to scale dynamically
- agility is the ability to react fast (scale quickly)
- fault tolerance is the ability to maintain system uptime while physical and service component failures happen
- disaster recovery is the process and design principle which allows a system to recovers from natural or human induced disasters
- high availability is the agreed level of operational uptime for the system. It is a simple calculation of system uptime versus whole lifetime of the system.
- availability = uptime/(uptime + downtime)
Whiłe cłoud computing contałns a number ot service types, tne tour most common ones by tne dennition are Compute Power, Storage, Analytics, and Networking. Increasing the size of the resource is called scaling up, hence decreasing the size is scaling down_ Because we move along the venjcal line, changing the size is called vertical scaling. Increasing the amount of instances of our resource is called scaling out, hence decreasing the amount is scaling in. Because we move along the horizontal line, changing the size is called horizontal scaling. Scalability is the system’s ability to scale (allocatel deallocate) resources_ Agility is the ability to scale quickly. Ił that scaling is happening automatically, then we are talking about Elasticity. All ot those terms directly explain the system’s ability to change resources at will. When the system is elastic that means ił can adjust iłs processing power to match the demand. This happens only when the system is able to allocate and deallocate resources dynamically Availability talks about system uptime, so wnen the system is available to users/otner applications. High Availability simply means that system is designed to run for a very long period of time