Understanding Cloud Concepts Flashcards
15-20% of the test
What is High Availability (HA)
The ability of the 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.
What is Scalability
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.
What is Vertical Scaling
The process of adding resources to increase the power of an existing server (e.g. adding a faster CPU, additional CPUs, more memory). (aka “scaling up”)
What is Horizontal Scaling
The process of adding more servers that function together as one unit (e.g. adding more servers). (aka “scaling out”)
What is Elasticity
Automatically add or remove resources based on demand.
What is Cloud Agility
Cloud agility is the 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).
What is Fault Tolerance
Redundancy is often built into cloud services architecture so if one component fails, a backup component takes its place. This is referred to as fault tolerance and it ensures that your customers aren’t impacted when an unexpected accident occurs.
What is 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.
What is Economies of Scale
Economies 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).
What is 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
What is Operational Expenditure
Ongoing costs
paid monthly or annually.
accounted for in the current month or year
operational costs
What is Infrastructure-as-a-Service
Infrastructure as a Service is the most flexible category of cloud services. 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 systems). Instead of buying hardware, with IaaS, you rent it. It’s an instant computing infrastructure, provisioned and managed over the internet.
What is Platform-as-a-Service
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.
What is Software-as-a-Service
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 licensed through a monthly or annual subscription. Office 365, Skype, and Dynamics CRM Online are perfect examples of SaaS software.
Compare and Contrast the responsibily of the user and the cloud provider for IaaS
USER: Purchase, installation, configuration, and management of their own software operating systems, middleware, and applications.
Provider: Responsible for ensuring that the underlying cloud infrastructure (such as virtual machines, storage, and networking) is available for the user.
Compare and Contrast the responsibily of the user and the cloud provider for PaaS
USER: Responsible for the development of their own applications.
Provider:Responsible for operating system management, and network and service configuration.
Compare and Contrast the responsibily of the user and the cloud provider for SaaS
Users: just use the application software; they are not responsible for any maintenance or management of that software Providers: The cloud provider is responsible for the provision, management, and maintenance of the application software.
What is the Public Cloud (most common)
This is the most common deployment model. In this case, you have no local hardware to manage or keep up-to-date – everything runs on your cloud provider’s hardware.
What is the Private Cloud (2nd most common)
In a private cloud, you create a cloud environment in your own datacenter and provide self-service access to compute resources to users in your organization.
What is a hybrid cloud
A hybrid cloud combines public and private clouds, allowing you to run your applications in the most appropriate location.
Compare & Contrast (Advantages & Disadvantages) of public cloud
Advantages: + High Scalability/Agility + PAYG (No CapEx, OpEx model) + Not responsible for hardware maintenance + Minimal technical knowledge required Disadvantages: - May not be able to meet specific security requirements - May not be able to meet specific compliance requirements - You don’t own the hardware and may not be able to manage them as you wish
Compare & Contrast (Advantages & Disadvantages) of Private cloud
Advantages: + You have complete control + Can meet strict security and compliance requirements Disadvantages - Upfront CapEx costs - Owning equipment limits agility to scale - Requires high technical knowledge
Compare & Contrast (Advantages & Disadvantages) of Hybrid cloud
Advantages: + Advantages of both Public and Private Disadvantages - Can be more expensive than selecting one deployment model - Can be more complicated to set up and manage
What are some of the benefits of cloud computing
- Cost Effective: Pay-as-you-go, consumption-based pricing model. Rather than paying for hardware up-front, you rent hardware and pay for the resources that you use. - Scalable: Increase or decrease the resources and services used based on the demand or workload at any given time. - Elastic: Automatically add or remove resources based on demand. - Current: Computer hardware and software is automatically maintained by the cloud provider. - Reliable: Cloud providers offer data backup, disaster recovery, and data replication services. Redundancy is often built into cloud services architecture so if one component fails, a backup component takes its place. - Global: Cloud providers have fully-redundant datacenters located in various regions all over the globe (performance, redundancy, compliance). - Secure: Cloud providers offer a broad set of policies, technologies, controls, and expert technical skills that can provide better security than most organizations can otherwise achieve.