Exam Review Flashcards
High Availability
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.
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.
Vertical Scaling (aka “scaling up”)
The process of adding resources to increase the power of an existing server (e.g. adding a faster CPU, 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).
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).
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.
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.
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).
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 billed 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.
Infrastructure-as-a-Service (IaaS) (shared responsibility model)
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.
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 licensed through a monthly or annual subscription. Office 365, Skype, and Dynamics CRM Online are perfect examples of SaaS software.
Describe the responsibilities of the different service models.
IaaS
User -
Purchase, installation, configuration, and management of their own software operating systems, middleware, and applications.
Cloud Provider - Responsible for ensuring that the underlying cloud infrastructure (such as virtual machines, storage, and networking) is available for the user.
PasS
User - Responsible for the development of their own applications.
Cloud Provider - Responsible for operating system management, and network and service configuration.
SaaS
User -
Users just use the application software; they are not responsible for any maintenance or management of that software.
Cloud Provider -
The cloud provider is responsible for the provision, management, and maintenance of the application software.
Public Cloud
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.
Private Cloud
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.
Hybrid Cloud
A hybrid cloud combines public and private clouds, allowing you to run your applications in the most appropriate location.
Advantages and Disadvantages of Cloud Models
Public
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
Private 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
Hybrid
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
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.
Geography
An Azure geography is a discrete market typically containing two or more regions that preserve data residency and compliance boundaries.
Current: Americas, Europe, Asia Pacific, Middle East and Africa
Region
A region is a geographical area on the planet containing at least one, but potentially multiple datacenters that are nearby and networked together with a low-latency network.
Example: North Europe, West Europe, Germany North, Germany West Central
Availability Zone
Availability Zones are physically separate datacenters within an Azure region. Each Availability Zone is made up of one or more datacenters equipped with independent power, cooling, and networking.
Availability Sets
Availability Sets comprise of update and fault domains. Update Domain: When a maintenance event occurs, the update is sequenced through update domains. Fault Domain: Fault domains provide for the physical separation of a workload across different hardware in the datacenter.
Hierarchy
Geography > Region > Availability Zone > Availability Set > Fault Domain/Update Domain
Region Pair
Each Azure region is always paired with another region within the same geography (such as US, Europe, or Asia) 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, or physical network outages affecting both regions at once.
Resource Group
Resource groups are a fundamental element of the Azure platform. A resource group is a logical container for resources deployed on Azure.
Azure Resource Manager
Azure Resource Manager is the interface for managing and organizing cloud resources. Think of Resource Manager as a way to deploy cloud resources.
Describe Compute Products (6)
Virtual Machines - Windows or Linux virtual machines (VMs) hosted in Azure
Virtual Machine Scale Sets - Scaling for Windows or Linux VMs hosted in Azure
App Service - PaaS offerings to build, deploy, and scale enterprise-grade web, mobile, and API apps.
Azure Functions - An event-driven, serverless compute service
Azure Container Instances (ACI) - Azure Container Instances (ACI) offers the fastest and simplest way to run a container in Azure. You don’t have to manage any virtual machines or configure any additional services. It is a PaaS offering that allows you to upload your containers and execute them directly with automatic elastic scale.
Azure Kubernetes (AKS) - The task of automating, managing, and interacting with a large number of containers is known as orchestration. Azure Kubernetes Service (AKS) is a complete orchestration service for containers with distributed architectures with multiple containers.
Describe Networking Products (5)
Virtual Network - Connects VMs to incoming Virtual Private Network (VPN) connections
Load Balancer - Balances inbound and outbound connections to applications or service endpoints
VPN Gateway Accesses Azure Virtual Networks through high-performance VPN gateways
Application Gateway - Optimizes app server farm delivery while increasing application security
Content Delivery Network - Delivers high-bandwidth content to customers globally
Describe Storage Products (4)
Blob Storage - Storage service for very large objects, such as video files or bitmaps
Disk Storage - Provides disks for virtual machines, applications, and other services.
File Storage - Azure Files offers fully-managed file shares in the cloud.
Archive Storage - Storage facility for data that is rarely accessed.
Describe Database Products (4)
CosmosDB Globally distributed database that supports NoSQL options
Azure SQL Database - Fully managed relational database with auto-scale, integral intelligence, and robust security
Azure Database Migration Service - Migrates your databases to the cloud with no application code changes
Azure SQL Data Warehouse - Fully managed data warehouse with integral security at every level of scale at no extra cost
Azure Marketplace
The Marketplace allows customers to find, try, purchase, and provision applications and services from hundreds of leading service providers, all certified to run on Azure. Azure Marketplace is a service on Azure that helps connect end users with Microsoft partners, independent software vendors (ISVs), and start-ups that are offering their solutions and services, which are optimized to run on Azure.
Describe Internet of Things (IoT) Services (3)
IoT Hub - Messaging hub that provides secure communications and monitoring between millions of IoT devices
IoT Central - Fully-managed global IoT software as a service (SaaS) solution that makes it easy to connect, monitor, and manage your IoT assets at scale
IoT Edge - Push your data analysis onto your IoT devices instead of in the cloud allowing them to react more quickly to state changes.
Describe Big Data and Analytics Services (3)
SQL Data Warehouse - Run analytics at a massive scale using a cloud-based Enterprise Data Warehouse (EDW) that leverages massive parallel processing (MPP) to run complex queries quickly across petabytes of data
HDInsight - Process massive amounts of data with managed clusters of Hadoop clusters in the cloud
Data Lake Analytics - On-demand (“pay as you go”) scalable analytics service that allows you to write queries to transform your data and extract valuable insights.
Describe Artificial Intelligence Services (2)
Azure Machine Learning Service - Cloud-based environment you can use to develop, train, test, deploy, manage, and track machine learning models. It can auto-generate a model and auto-tune it for you. It will let you start training on your local machine, and then scale out to the cloud
Azure Machine Learning Studio - Collaborative, drag-and-drop visual workspace where you can build, test, and deploy machine learning solutions using pre-built machine learning algorithms and data-handling modules
Describe Serverless Computing Services (3)
Azure Functions - An event-driven, serverless compute service
Logic Apps - Help you automate and orchestrate tasks, business processes, and workflows when you need to integrate apps, data, systems, and services across enterprises or organizations.
Event Grid - Allows you to easily build applications with event-based architectures. It’s a fully-managed, intelligent event routing service that uses a publish-subscribe model for uniform event consumption.