Fundamentals Module 2 Flashcards
Core architectural component groups
- physical infrastructure
- management infrastructure
Datacenter
facilities with resources arranged in racks, with dedicated power, cooling, and networking infrastructure.
NB: individual datacenters aren’t directly accessible
Regions
- a geographical area on the planet that contains at least one, but potentially multiple data centers that are nearby and networked together with a low-latency network.
- minimum of three separate availability zones are present in all availability zone-enabled regions
Availability Zones
- physically separate data centres within an Azure region
- each availability zone is made up of one or more data centres equipped with independent power, cooling, and networking
- connected through high-speed, private fiber-optic networks.
NB not all Azure Regions currently support availability zones.
Azure services that support availability zones fall into three categories:
- Zonal services: You pin the resource to a specific zone (for example, VMs, managed disks, IP addresses).
- Zone-redundant services: The platform replicates automatically across zones (for example, zone-redundant storage, SQL Database).
- Non-regional services: Services are always available from Azure geographies and are resilient to zone-wide outages as well as region-wide outages.
Region pairs
- Most Azure regions are paired with another region within the same geography (such as US, Europe, or Asia) at least 300 miles away
- if a region in a pair was affected by a natural disaster, services would automatically fail over to the other region in its region pair.
Advantages of regional pairs
1.Pair of regions are a) directly connected b) far enough apart to be isolated from regional disasters => provide reliable services and data redundancy.
- If an extensive Azure outage occurs, one region out of every pair is prioritized to make sure at least one is restored as quickly as possible for applications hosted in that region pair.
- Planned Azure updates are rolled out to paired regions one region at a time => minimize downtime and risk of application outage.
- Data continues to reside within the same geography as its pair (except for Brazil South) for tax- and law-enforcement jurisdiction purposes.
Sovereign Regions
instances of Azure that are isolated from the main instance of Azure.
May need to use a sovereign region for compliance or legal purposes.
Azure resource
basic building block of Azure, anything you create, provision, deploy
Examples: Virtual Machines (VMs), virtual networks, databases, cognitive services
Resource groups
- groupings of resources
- every resource needs to be placed into a resource group
- a resource group can contain many resources, a single resource can only be in one resource group at a time
- resource groups can’t be nested
Azure subscriptions
- subscriptions are a unit of management, billing, and scale
- a subscription provides authenticated and authorized access to Azure products and services
- It allows to provision resources
- An Azure subscription links to an Azure account, which is an identity in Azure Active Directory (Azure AD) or in a directory that Azure AD trusts
- In a multi-subscription account, you can use the subscriptions to configure different billing models and apply different access-management policies
Types of subscription boundaries
- Billing boundary
- Access control boundary
Billing boundary
- how an Azure account is billed for using Azure
- Azure generates separate billing reports and invoices for each subscription so that you can organize and manage costs.
Access control boundary
- Azure applies access-management policies at the subscription level
Subscriptions use cases
create additional subscriptions to separate:
- Environments (dev / test) resource AC is at the subscription level
- Organizational structures (IT, marketing)
- Billing: osts are first aggregated at the subscription level, you might want to create subscriptions to manage and track costs based on your needs. i.e. one subscription for your production workloads and another subscription for your development and testing workloads
Azure management groups
- organize subscriptions into containers called management groups and apply governance conditions to the management groups
- management groups can be nested.
- A management group tree can support up to six levels of depth. This limit doesn’t include the root level or the subscription level.
- Each management group and subscription can support only one parent.
Hierarchy
- resource
- resource group
- subscription (highest level to lock)
- management group
Virtual machine scale sets
- let you create and manage a group of identical, load-balanced VMs
- allow you to centrally manage, configure, and update a large number of VMs in minutes
- the number of VM instances can automatically increase or decrease in response to demand, or you can set it to scale based on a defined schedule
- Virtual machine scale sets also automatically deploy a load balancer to make sure that your resources are being used efficiently
Virtual machine availability sets
- designed to ensure that VMs stagger updates and have varied power and network connectivity, preventing you from losing all your VMs with a single network or power failure.
- Availability sets do this by grouping VMs in two ways: update domain and fault domain.
Update domain
- VMs that can be rebooted at the same time
- Update group going through the update process is given a 30-minute time to recover before maintenance on the next update domain starts
Fault domain
- groups your VMs by common power source and network switch
- an availability set will split your VMs across up to three fault domains
VM use cases
- During testing and development
- When running applications in the cloud
- When extending your datacenter to the cloud
- During disaster recovery (while primary datacenter is not available)
- Move to the cloud with VMs
VM Resources
- Size (purpose, number of processor cores, and amount of RAM)
- Storage disks (hard disk drives, solid state drives, etc.)
- Networking (virtual network, public IP address, and port configuration)
Azure Virtual Desktop
- is a desktop and application virtualization service that runs on the cloud. It enables you to use a cloud-hosted version of Windows from any location
- With Azure Virtual Desktop, the data and apps are separated from the local hardware.
- The actual desktop and apps are running in the cloud, meaning the risk of confidential data being left on a personal device is reduced
- user sessions are isolated in both single and multi-session environments.
VM vs container
- a single operating system per virtual machine
- if you want to run multiple instances of an application on a single host machine, containers are an excellent choice
- containers are more agile
Containers
- virtualization environment
- can run multiple containers on a single physical or virtual host
- you don’t manage the operating system for a container
- are lightweight and designed to be created, scaled out, and stopped dynamically
Azure Container Instances
PaaS
1. allow you to upload your containers and then the service will run the containers for you
- run container without having to manage any virtual machines or adopt any additional services
Azure Container Apps
Paas
1. like azure container instance
- allow you to get up and running right away, they remove the container management piece
- extra benefit: ability to incorporate load balancing and scaling
Azure Kubernetes Service
a container orchestration service.
Azure Functions
- an event-driven, serverless compute option that doesn’t require maintaining virtual machines or containers
- an event wakes the function, alleviating the need to keep resources provisioned when there are no events
- scale automatically based on demand, so they may be a good choice when demand is variable
- runs your code when it’s triggered and automatically deallocates resources when the function is finished
Benefits of Azure functions
- you’re only concerned about the code running your service and not about the underlying platform or infrastructure
- you need to perform work in response to an event (often via a REST request), timer, or message from another Azure service, and when that work can be completed quickly, within seconds or less.
Azure hosting options
- virtual machine (VM)
- containers
- Azure App Service
Types of app services
- Web apps
- API apps
- WebJobs
- Mobile apps
Azure App service
- enables you to build and host web apps, background jobs, mobile back-ends, and RESTful APIs in the programming language of your choice without managing infrastructure
- offers automatic scaling and high availability
- enables automated deployments
- an HTTP-based service for hosting web applications, REST APIs, and mobile back ends
Azure App Service manages the following infrastructure decisions
- Deployment and management are integrated into the platform.
- Endpoints can be secured.
- Sites can be scaled quickly to handle high traffic loads.
- The built-in load balancing and traffic manager provide high availability.
WebJobs
- use to run a program (.exe, Java, PHP, Python, or Node.js) or script (.cmd, .bat, PowerShell, or Bash) in the same context as a web app, API app, or mobile app.
- can be scheduled or run by a trigger.
- WebJobs are often used to run background tasks as part of your application logic.
Azure virtual networks capabilities
- Isolation and segmentation
- Internet communications
- Communicate between Azure resources
- Communicate with on-premises resources
- Route network traffic
- Filter network traffic
- Connect virtual networks
Isolation and segmentation
Azure virtual network allows you to create multiple isolated virtual networks.
Mechanisms to establish on prem connectivity
- Point-to-site virtual private network connections
- Site-to-site virtual private networks
- Azure ExpressRoute
Point-to-site virtual private network
- a computer outside your organization back into your corporate network
- the client computer initiates an encrypted VPN connection to connect to the Azure virtual network.
Site-to-site virtual private networks
- link your on-premises VPN device or gateway to the Azure VPN gateway in a virtual network
- The connection is encrypted and works over the internet
Azure ExpressRoute
a dedicated private connectivity to Azure that doesn’t travel over the internet
Network security groups
- Azure resources that can contain multiple inbound and outbound security rules.
- can define these rules to allow or block traffic, based on factors such as source and destination IP address, port, and protocol
- ) DOES NOT encrypt traffic.
Network virtual appliances
specialized VMs that can be compared to a hardened network appliance. A network virtual appliance carries out a particular network function, such as running a firewall or performing wide area network (WAN) optimization.
Virtual network peering
- allows two virtual networks to connect directly to each other
- Network traffic between peered networks is private, and travels on the Microsoft backbone network, never entering the public internet
virtual private network (VPN)
- uses an encrypted tunnel within another network
- typically deployed to connect two or more trusted private networks to one another over an untrusted network
- traffic is encrypted while traveling over the untrusted network
NB
1. only one VPN gateway in each virtual network
2. can use one gateway to connect to multiple locations
Types of VPN
- policy based
- route based
The primary distinction is how they determine which traffic needs encryption
Policy-based VPN
specify statically the IP address of packets that should be encrypted through each tunne
Route-based gateways
IP routing (either static routes or dynamic routing protocols) decides which one of these tunnel interfaces to use when sending each packet
NB more resilient to topology changes such as the creation of new subnets.
How to maximise VPN resiliency
- Active/standby
- Active/active
- ExpressRoute failover
- Zone-redundant gateways
Active/standby
(default)
1. VPN gateways are deployed as two instances in an active/standby
2. connections restored within a few seconds for planned maintenance and within 90 seconds for unplanned disruptions.
Active/active
can also deploy VPN gateways in an active/active configuration. In this configuration, you assign a unique public IP address to each instance. You then create separate tunnels from the on-premises device to each IP address
ExpressRoute failover
configure a VPN gateway as a secure failover path for ExpressRoute connections
Zone-redundant gateways
- Deploying gateways in Azure availability zones physically and logically separates gateways within a region while protecting your on-premises network connectivity to Azure from zone-level failures
- These gateways require different gateway stock keeping units (SKUs) and use Standard public IP addresses instead of Basic public IP addresses.
Features and benefits of ExpressRoute
(as the connection service between Azure and on-premises networks.)
- Connectivity to Microsoft cloud services across all regions in the geopolitical region
- Global connectivity to Microsoft services across all regions with the ExpressRoute Global Reach.
- Dynamic routing between your network and Microsoft via Border Gateway Protocol (BGP).
- Built-in redundancy in every peering location for higher reliability.
ExpressRoute connectivity models
- CloudExchange colocation
- Point-to-point Ethernet connection
- Any-to-any connection
- Directly from ExpressRoute sites
Co-location at a cloud exchange
- your datacenter, office, or other facility being physically co-located at a cloud exchange, such as an ISP.
- can request a virtual cross-connect to the Microsoft cloud.
Any-to-any networks
integrate your wide area network (WAN) with Azure by providing connections to your offices and datacenters. Azure integrates with your WAN connection to provide a connection like you would have between your datacenter and any branch offices.
Benefits of Azure DNS
- Reliability and performance
- Security
- Ease of Use
- Customizable virtual networks
- Alias records
Storage account in azure
- provides a unique namespace for your Azure Storage data that’s accessible from anywhere in the world over HTTP or HTTPS
- Data in this account is secure, highly available, durable, and massively scalable
- must have a unique-in-Azure account name.