Deploy and manage Azure compute resources Flashcards
What cloud service model does an Azure VM classify as?
infrastructure as a service (IaaS).
What is the responsibility of the cloud service provider in the infrastructure as a service (IaaS) cloud service model?
Datacenter/physical networking and hosts.
By default, do Azure VMs and networks communicate with external IPs?
No; Services outside the virtual network can’t connect to services within the virtual network.
How is the VM name determined?
Computer name set in the OS.
What is the max amount of characters that a VM name can be?
15 for windows, 64 for linux.
When choosing a VM name what is best practice?
Choose names that are meaningful and consistent to identify what the virtual machine does and where it is located.
What are common elements that can be included in the VM name?
Environment/purpose; Location; Instance/version; Service/Role.
When utilizing an Azure VM, what two components make up the total cost of VM usage?
Compute and Storage.
To better keep track of the compute and storage costs of an Azure VM, what is best practice?
Separate billing costs to better understand usage.
How are VM compute resources priced and billed?
Priced on a per-hour basis but billed on a per-minute basis.
What determines the ultimate cost of VM compute resources?
Price varies based on the virtual machine config and and operating system.
What are the two compute expense payment options?
- Consumption-based
- Reserved Virtual Machine Instances
Describe ‘Consumption-based’ compute expensing for Azure VMs
Pay for compute capacity by the second and able to scale/stop at any time.
What is the best use case for consumption based compute expensing for Azure VMs?
Applications with short-term or unpredictable workloads that can’t be interrupted.
Describe ‘Reserved Virtual Machine Instances’ compute expensing for Azure VMs
An upfront purchase of a VM for one or three years in a specified region.
What is the benefit of using reserved VM Instances?
72% price savings compared to pay-as-you-go pricing.
Can a reserved VM instance be terminated early or scaled?
Yes; Exchanged or returned for an early termination fee.
What is the best use case for reserved VM Instances?
If the virtual machine has to run continuously, or you need budget predictability.
How are storage expenses priced and billed for Azure VM instances?
Charged separately for the Azure Storage used by the virtual machine.
If a VM is powered off, or deleted, how is storage priced/billed?
Status of the VM has no relation to the Azure Storage charges incurred; Always charged for any Azure Storage used by the disks.
Can Azure VM host more than Windows/Linux OS?
Yes; Azure marketplace has install images for a variety of OS and other virtual systems/networking images.
How are VM capabilities determined?
Azure provides different configs that come with different levels of CPU, Memory, and storage instead of specifying them independently.
What is best practice when determining VM sizing and capabilities?
Consider the type of workload your virtual machine needs to run.
What are the Azure provided VM size classifications?
General purpose; Compute optimized; Memory optimized; Storage optimized; GPU; High performance computes.
By default, how many virtual disks (VHDs) are allocated to a VM?
Two disks: an operating system disk and a temporary disk.
Can additional virtual hard disks (VHDs) be added to a VM?
Yes; Also known as data disks.
Describe an OS virtual hard disk (VHD)
A pre-installed operating system registered as a SATA drive; Labeled “c:” by default.
What is best practice for utilizing a temporary disk?
Any data on the temporary drive shouldn’t be data that’s critical to the system or any application on the system.
What does Azure register a data disk as?
Registered as SCSI drives and are labeled with a letter you choose.
What is the max amount of VM storage Azure provides?
256TB
What is an Azure-managed virtual hard disk (VHD) stored as in Azure storage?
Stored as page blobs
Define ‘Azure Bastion’
Fully managed PaaS; Provides RDP/SSH connectivity to your virtual machines directly over SSL without the need for a public IP.
What is the best use case for a general purpose VM classification?
Testing/development; Small DBs; Low-Med traffic web servers.
What is the best use case for a compute optimized VM classification?
Medium traffic web servers; Network appliances; App servers.
What is the best use case for a memory optimized VM classification?
Relational DBs; med-large caches; in-memory analytics.
When managing an Azure VM, how should maintenance and downtime be considered?
An availability plan should be created; Include strategies for unplanned hardware maintenance, unexpected downtime, and planned maintenance.
Describe an availability set and its purpose
Logical grouping/deployment to ensure a group of related virtual machines are deployed and managed together.
What is best practice when placing VMs in an availability set?
All VMs should perform the identical set of functionalities and have the same software installed.
To ensure availability, how does Azure manage VMs in an availability set?
VMs in an availability set run across multiple physical servers, compute racks, storage units, and network switches.
Can a VM and an availability set be created at the same time?
Yes.
Can a VM be added to an availability set after its created?
No; Can only be added to an availability set when the virtual machine is created.
How/where can availability sets be created?
Azure portal, Azure Resource Manager (ARM) templates, scripting, or API tools.
Does Microsoft Azure provide SLAs for VMs?
Yes.
In regards to a VM availability set, what are the two node concepts Azure uses to ensure high availability when deploying or upgrading applications across an availability set?
Update domains and fault domains.
Define an “update domain”
A group of nodes that are upgraded together during the process of a service upgrade (or rollout).
What is the purpose/function of an update domain?
Allows Azure to perform incremental or rolling upgrades across a deployment.
How should VMs be organized into update domains?
a set of VMs and associated physical hardware that can be updated and rebooted at the same time.
When there is planned maintenance, how many update domains are updated at a time?
One at a time.
How many default update domains does Azure provide?
5
How many custom update domains can a tenant configure?
20 max
Define a ‘fault domain’
A group of nodes that belong to the same physical rack/switch that share a singe point of failure.
How many fault domains are needed to mitigate against hardware failures, network outages, power interruptions, or software updates?
2
When placing VMs in an availability set, how are the VMs organized in the datacenter?
Each VM is located in a different fault domain.
Define the purpose of an ‘availability zone’ and its logical makeup
Protects your applications and data from datacenter failures by combining a fault domain and an update domain.
What is the physical representation of an availability zone?
Availability zones are unique physical locations within an Azure region.
What does an availability zone consist of physically?
One or more datacenters that are equipped with independent power, cooling, and networking.
How many availability zones are in an azure region?
A minimum of three separate zones in all enabled regions.
What are the Azure resources and services that can use availability zones?
VMs and managed disks; Standard IP addresses; Zone-redundant Azure storage; Azure SQL.
Describe a scalable VM
Can handle increases in requests without adversely affecting response time and throughput.
What are the two types of scaling?
Vertical and Horizontal.
Define ‘vertical scaling’
Increasing or decreasing the virtual machine size and compute power in response to a workload.
Define ‘horizontal scaling’
Used to adjust the number of virtual machines in your configuration to support the changing workload.
Between vertical and horizontal scaling, which has the least limitations and why?
Horizontal scaling has less limitations because depending on the vm size there can be a limit and vertical scaling requires the vm to stop and start.
Define ‘VM reprovisioining’
The process of removing an existing virtual machine and replacing it with a new machine.
Describe a ‘Virtual Machine Scale Set’
an Azure Compute resource that you can use to deploy and manage a set of identical virtual machines.
What is the purpose of Virtual Machine Scale Sets?
To automatically increase/decrease the number of VMs as application demand fluctuates.
What are the characteristics of the VMs in a Virtual Machine Scale Set?
All VMs created from set have the same base operating system image and configuration.
Can Azure load balancer direct traffic to a VM scale set?
Yes.
How do VMs in a scale set that use a load a balancer receive traffic?
They are treated as a pool.
What is the max amount of VMs that can be created with a VM set?
1000 VMs or up to 600 for custom VM images.
What is the orchestration mode when configuring a VM scale set?
Determines how VMs are managed and deployed by the scale set.
What are the two orchestration modes Azure offers for VM scale sets?
- flexible
- uniform
Define ‘flexible’ VM scale set orchestration
You must manually create and add a virtual machine of any configuration to the scale set.
Define ‘uniform’ VM scale set orchestration
Define a virtual machine model and Azure will generate identical instances based on that model.
When configuring a VM scale set, how is autoscaling configured?
By determining initial instance count, mi and max instance count, and the thresholds to scale in/out.
Which Virtual Machine Scale Sets feature can be configured to add VMs during peak production?
Schedule-based rules.
Define an ‘App service plan’
Defines a set of compute resources for a web application to run.
What does an ‘app service plan’ consist of?
Computer resources needed to run a web app - similar to an app pool or server farm.
How many applications can be configured to run in the same app service plan?
One or more.
What 3 setting must be defined when configuring an app service plan?
- Region
- Number of VMs
- Size/config of VMs in the plan.
Can new applications/VMs be added to an existing app service plan?
Yes; As long as the plan has enough resources.
How can apps/VMs scale in a free/shared tier app service plan?
Apps/VMs can’t scale out.
What are the two autoscaling rules?
- Metric based
- time-based (schedule-based)
Define ‘metric based’ autoscaling
Measures application load to add or remove VMs based on the load.
Define ‘time-based (schedule-based)’ autoscaling
Allow you to scale based on ranges of time.
Which App Service Plan can you implement to support a Production team’s requirements?
Premium.
Define ‘Azure app service’
Combines everything needed to create websites, mobile backends, and web APIs for any platform or device.
When creating an app in azure app service, what must be remembered when specifying a name?
The name for your app must be globally unique.
What are the two ways Azure app service can publish applicatoins?
As code or as a docker container.
What are the two methods used to deploy an application through Azure app service?
- Automated
- Manual
What subdomain does Azure assign to an app created in Azure app service?
azurewebsites.net
To backup and restore an azure app service, what is required?
storage account and container in the same subscription as the app and standard/premium tier app service.
When backing up an azure app with app service, what is included in the backup?
- App configuration settings
- File content
- Any database connected to your app
Describe a backup file and its contents
A zip file with backup data and an XML manifest file.
What is the max amount of data a backup can hold?
Up to 10 GB of app and database content.
Describe ‘Azure Application Insights’
a feature of Azure Monitor that lets you monitor your live applications by integrating the app service with application insights.
What cloud deployment models does application insights function with?
On-premises, in a hybrid environment, or in any public cloud.
When you clone a configuration from another deployment slot, which configuration setting follows the content across the swap?
Connection strings.
Define a ‘deployment slot’
Help you organize different app stages; Development, test, stage, and production.
Define ‘Containerization’
Allows you to virtualize the operating system; Containers within a virtual machine provide functionality similar to that of virtual machines within a physical server.
What is the purpose of containerization?
Allows you to virtualize the operating system and run multiple applications within the same instance of an operating system, while maintaining isolation between the applications.
Which technology provides a stronger security boundary, containers or VMs?
VMs because it provides complete isolation from the host OS and other VMs, while containers are hosted on the same OS.
What are common ways to deploy a container?
Docker via CLI or Azure Kubernetes service.
What persistent storage method do containers in Azure utilize?
Azure Disks for local storage for a single node, or Azure Files (SMB shares) for storage shared by multiple nodes or servers.
How are containers created?
From a container image.
Define a container image
A lightweight, standalone, executable package of software that includes everything to run an application.
What are the 5 components of a container image?
- Code
- Runtime
- System Tools
- System libraries
- Settings
What is the purpose of code in a container image?
Provides the applicaitons source code.
What is the purpose of the runtime component in a container image?
Provides the environment required to execute the application.
What is the purpose of the system tools component in a container image?
Utilities necessary for the application to function.
What is the purpose of the system libraries component in a container image?
Shared libraries used by the application.
What is the purpose of the settings component in a container image?
Configuration parameters specific to the application.
What is the top-level resource for a container in Azure Container Instances?
A container group.
Define a ‘container group’
A collection of containers that get scheduled on the same host machine.
How does Azure container instances allocate resources for a container or a container group?
By adding together the resource requests (CPUs, memory, and GPUs) of all containers in the group.
What are the two ways to deploy a container in Azure container instances.
- Azure Resource Manager (ARM) Template
- YAML file
Can container groups share the same external facing IP or multiple ports on the same IP?
Yes
Are containers in a container group scheduled on a single host?
Yes as well as the same DNS name.
What are common uses of Azure container apps/instances?
Deploying API endpoints
Hosting background processing jobs
Handling event-driven processing
Running microservices.
What cloud service model does Azure container apps follow?
PaaS
What is Azure container apps designed for?
Designed for microservices and serverless applications.
How are containers in Azure container instance billed?
Billing for Container Instances occurs when containers are in use.
What cloud service model does Azure app service fall under?
A fully managed platform as a service (PaaS)
How do containers in a container group interact with each other?
Containers in the group share a lifecycle, resources, local network, and storage volumes.
