Azure architecture and services Flashcards
Azure Region
A region is a geographical area on the planet that contains at least one, but potentially multiple datacentres that are nearby and networked together with a low-latency network.
Availability Zones
Availability zones are physically separate datacentres within an Azure region. Each availability zone is made up of one or more datacentres equipped with independent power, cooling, and networking.
Region pairs
Most Azure regions are paired with another region within the same geography at least 300 miles away. For example, 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.
Examples of region pairs in Azure
West US paired with East US and South-East Asia paired with East Asia.
Brazil South Region
Brazil South is unique because it’s paired with a region outside of its geography. Brazil South’s secondary region is South Central US. The secondary region of South Central US isn’t Brazil South.
West India Region
West India’s secondary region is South India, South India does not rely on West India. West India’s secondary region is South India, but South India’s secondary region is Central India.
Sovereign Regions
Sovereign regions are instances of Azure that are isolated from the main instance of Azure.
Azure sovereign regions include:
US DoD Central, US Gov Virginia, US Gov, China East, China North, and more
Azure US sovereign regions
These regions are physical and logical network-isolated instances of Azure for U.S. government agencies and partners. These datacentres are operated by screened U.S. personnel and include additional compliance certifications.
Azure China sovereign regions
These regions are available through a unique partnership between Microsoft and 21Vianet, whereby Microsoft doesn’t directly maintain the datacentres.
Azure resources
A resource is the basic building block of Azure. Anything you create, provision, deploy, etc. is a resource. Virtual Machines (VMs), virtual networks, databases, cognitive services, etc.
Resource groups
Resource groups are simply groupings of resources. When you create a resource, you’re required to place it into a resource group.
Can a single resource be in two resource groups?
While a resource group can contain many resources, a single resource can only be in one resource group at a time.
Azure subscriptions
Using Azure requires an Azure subscription. A subscription provides you with authenticated and authorized access to Azure products and services. It also allows you to provision resources.
Billing boundary
This subscription type determines 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, and you can create separate subscriptions to reflect different organizational structures.
Azure management groups
Azure management groups provide a level of scope above subscriptions. You organize subscriptions into containers called management groups and apply governance conditions to the management groups.
How many management groups can be supported in a single directory?
10,000 management groups can be supported in a single directory.
How many levels can a management group tree support?
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.
True? or False?
True
Naming your storage account
Storage account names must be between 3 and 24 characters in length and may contain numbers and lowercase letters only. No two storage accounts can have the same name.
Azure Storage Redundancy
Redundancy ensures that your storage account meets its availability and durability targets even in the face of failures. Azure Storage always stores multiple copies of your data.
Redundancy in the primary region
Data in an Azure Storage account is always replicated three times in the primary region.
What two options Azure Storage offers for how your data is replicated in the primary region?
Locally redundant storage (LRS) and zone-redundant storage (ZRS).
Locally redundant storage (LRS)
Locally redundant storage (LRS) replicates your data three times within a single data centre in the primary region.
Zone-redundant storage (ZRS)
For Availability Zone-enabled Regions, zone-redundant storage (ZRS) replicates your Azure Storage data synchronously across three Azure availability zones in the primary region.
ZRS (Zone-redundant storage) durability for Azure storage
ZRS (Zone-redundant storage) offers durability for Azure Storage data objects of at least 12 nines (99.9999999999%) over a given year.
LRS (Locally redundant storage) durability for Azure storage
Locally redundant storage provides at least 11 nines of durability (99.999999999%) of objects over a given year.
Scenarios for using ZRS (Zone-redundant storage)
Microsoft recommends using ZRS in the primary region for scenarios that require high availability. ZRS is also recommended for restricting replication of data within a country or region to meet data governance requirements.
Redundancy in a secondary region
For applications requiring high durability, you can choose to additionally copy the data in your storage account to a secondary region that is hundreds of miles away from the primary region.
Two options for copying your data to a secondary region.
Azure Storage offers two options for copying your data to a secondary region: geo-redundant storage (GRS) and geo-zone-redundant storage (GZRS).
What is Azure Storage RPO?
The interval between the most recent writes to the primary region and the last write to the secondary region is known as the recovery point objective (RPO).
How long is Azure Storage RPO?
Azure Storage typically has an RPO of less than 15 minutes, although there’s currently no SLA on how long it takes to replicate data to the secondary region.
Geo-redundant storage (GRS)
GRS synchronously replicates your data three times within the primary region and asynchronously to a secondary region using LRS.
Geo-redundant storage (GRS) durability
GRS offers durability for Azure Storage data objects of at least 16 nines (99.99999999999999%) over a given year.
Geo-zone-redundant storage (GZRS)
GZRS storage replicates data across three Azure availability zones in the primary region and to a secondary geographic region using LRS for disaster protection.
Geo-zone-redundant storage (GZRS) durability
GZRS is designed to provide at least 16 nines (99.99999999999999%) of durability of objects over a given year.
Describe Azure virtual machines
Azure VMs offer Infrastructure as a Service (IaaS) through virtualized servers, providing flexibility without the need to purchase or maintain physical hardware.
Scale VMs in Azure
Azure offers options to run single VMs or group them for increased availability, scalability, and redundancy. Features like scale sets and availability sets help manage VM grouping efficiently.
Virtual machine scale sets
Virtual machine scale sets enable the creation and management of a load-balanced group of identical VMs. Instances can auto-scale based on demand or follow a predefined schedule.
Virtual machine availability sets
Availability sets help create a resilient environment by staggering updates and diversifying power and network connections for VMs, preventing potential losses from a single failure.
Availability sets grouping VMs ways
Availability sets do grouping VMs in two ways: update domain and fault domain.
Update domain groups VMs
Update domains group VMs for simultaneous reboots during updates. Only one group is offline at a time, ensuring continuous operation. Each update group has a 30-minute recovery time before the next group undergoes maintenance.
Fault domain groups VMs
Fault domains categorize VMs based on power source and network switch. An availability set typically divides VMs across up to three fault domains, safeguarding against physical power or networking issues by spreading VMs across different domains.
VM Resources
Size ( 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)
Describe Azure virtual desktop
Azure Virtual Desktop is a cloud-based service for desktop and app virtualization. It’s compatible with various devices, operating systems, and accessible through dedicated apps or most modern browsers.
What are containers?
Containers are like running multiple virtual machines on one host, but unlike VMs, you don’t handle the container’s operating system.