Azure Terminology Flashcards
High Availability
The ability of an application to continue running in a healthy state, without significant downtime. By “healthy state,” we mean the application is responsive, and users can connect to the application and interact with it.
Scalability
Ability of a system to handle growth of users or work. NOTE: This is NOT automatically done. Increase or decrease the resources and services used based on the demand or workload at any given time. Vertical Scaling (aka “scaling up”) - add more resources to existing servers. Horizontal Scaling (aka “scaling out”) - add more servers.
Vertical Scaling (aka “scaling up”)
The process of adding more resources to increase the power of an existing server (a.g. adding a faster CU, additional CPUs, more memory)
Horizontal Scaling (aka “scaling out”)
The process of adding more servers that function together as one unit (e.g. adding more servers)
Elasticity
Ability of a system to <i>automatically</i> grow and shrink based on application demand.
Agility
Ability to rapidly change an IT infrastructure in order to adapt to the evolving needs of the business (e.g. if your service peaks one month, you can scale to demand and pay a larger bill for the month. If the following month the demand drops, you can reduce the used resources and be charged less).
Fault Tolerance
Ability of a system to handle faults like power, networking, or hardware failures. This is accomplished by building redundancy into the system.
Disaster Recovery
The ability to recover from rare but major incidents: non-transient, wide-scale failures, such as service disruption that affects an entire region. Disaster recovery includes data backup and archiving, and may include manual intervention, such as restoring a database from backup.
Economics of Scale
Economics of scale is the ability to do things more efficiently or at a lower-cost per unit when operating at a larger scale (e.g. the ability to acquire hardware at a lower cost than if a single user or smaller business were purchasing it, cloud providers can also make deals with local governments and utilities to get tax savings, lower pricing on power, cooling, and high-speed network connectivity between sites.) An example of this is Costco or Sam’s Club. They buy in bulk, and you as a customer benefit by purchasing a unit at a small rate than you could acquire on your own.
Capital Expenditure (CapEx)
CapEx is the spending of money on physical infrastructure up front, and then deducting that expense from your tax bill over time. CapEx is an upfront cost, which has a value that reduces over time.
Operational Expenditure (OpEx)
OpEx is spending money on services or products now and being billing for them now. You can deduct this expense from your tax bill in the same year. There is no upfront cost; you pay for a service or product as you use it. This is like the “pay-as-you-go” phone.
Infrastructure-as-a-Service (Iaas)
IaaS is the most flexible category of cloud computing. It aims to give you complete control over the hardware that runs your application (IT infrastructure servers and virtual machines (VMs), storage, networks, and operating system). Instead of buying hardware, with IaaS, you rent it. It’s an instant computing infrastructure, provisioned and managed over the internet.
Platform-as-a-Service (PaaS)
PaaS provides an environment for building, testing, and deploying software applications. The goal of PaaS is to help you create an application quickly without managing the underlying infrastructure. For example, when deploying a web application using PaaS, you don’t have to install an operating system, web server, or even system updates. PaaS is a complete development and deployment environment in the cloud.
Software-as-a-Service (Saas)
SaaS is software that is centrally hosted and managed for the end customer. It is usually based on an architecture where one version of the application is used for all customers, and licenses through a monthly or annual subscription. Office 365, Skype, and Dynamics CRM Online are perfect examples of SaaS.
Public Cloud
In this model, you have no hardware to manage or keep up-to-date - everything runs on your cloud provider’s hardware.
Private Cloud
Model where a company creates their own data center and provides access to compute resources to users in your organization.
Hybrid Cloud
This is known as “cloud bursting” or segmenting your organizations work as you move to the cloud. In this model, you combine both the public cloud and your private cloud to compose your IT portfolio. Additionally, some companies may decide that some of their applications are better in their private cloud, and vice-versa with the public cloud.
Azure Geography
A discrete market typically containing two or more regions that preserve data residency and compliance boundaries. Examples are: America, Europe, Asia Pacific, Middle East and Africa.
Region
A geographical area on the planet containing at least one, but potentially multiple data centers that are nearby and networked together with a low-latency network.
Availability Zone
Physically separate data centers within an Azure region. Each zone is made up of one or more data centers equipped with independent power, cooling and networking.
Availability Sets
A logical grouping capability for isolating VM resources from each other when they’re deployed.
Comprise of update and fault domains.
Update Domain: When a maintenance event occurs, the update is sequenced through update domains.
Fault Domains: Fault domains provide for the physical separation of a workload across different hardware in the datacenter.
Hierarchy of Azure Entities?
Geography -> Region -> Availability Zone -> Availability Set -> Fault Domain/Update Domain
Region Pair
The concept of pairing one region with another within the same geography (e.g. US, Europe, Asia, etc.) at least 300 miles away. This approach allows for the replication of resources (such as virtual machine storage) across a geography that helps reduce the likelihood of interruptions due to events such as natural disasters, civil unrest, power outages, physical network outages, or patches and updates.
Resource Group
A logical container for resources deployed on Azure.
Azure Resource Manager
An interface for managing and organizing cloud resources. This is a way to deploy cloud resources.
Virtual Machines (VMs)
Windows or Linux flavor, this allows one to have a virtualized set of hardware hosted in Azure.
Virtual Machine Scale Set
Offers a built-in load-balancer. This solution allows you to automatically increase/decrease the number of VMs one has running, create rules for what’s acceptable performance (or create a schedule) before spinning up another VM, and creates redundancy in the system.
